KR20000006477A - Positive photosensitive resin composition - Google Patents

Abstract

PURPOSE: A positive photoresist resin composite is provided to give good residual film ratio, pattern profile and definition without development defect when be exposed by ArF excimer laser beam. Further, a resist film acquired from it has a good dry etching proof feature. CONSTITUTION: The present invention discloses a positive photoresist resin composite comprising:(A) compound generating acid by the radiation of chemical ray; (B) polymer having particular structure such as those displayed by chemical formula (1a), (1b), (1c) and (1d) disclosed in a specification; (C) basic compound containing nitrogen; and (D) at least one fluorine type detergent and silicon type detergent. Therefore, the composite according to the present invention is effectively used to form fine patterns necessary to manufacture a semiconductor.

Description

Positive photosensitive resin composition {POSITIVE PHOTOSENSITIVE RESIN COMPOSITION}

FIELD OF THE INVENTION The present invention relates to positive photosensitive resin compositions for use in semiconductors, for example in the manufacture of semiconductors for ICs, in the manufacture of circuit boards for liquid crystals, thermal heads and the like, and in other photofabrication processes. More specifically, the present invention is a positive photosensitive resin composition suitable for use in semiconductor microprocesses, for example, using short wavelength energy rays such as, for example, far ultraviolet rays, X-rays, or electron beams, and using ArF excimer lasers. It is about.

In semiconductor integrated circuits, the degree of integration has recently increased, and LSI and VLSI have been put to practical use. With this trend, the minimum pattern line width of the integrated circuit and the like has reached the sub-half-micron region, and is decreasing further.

As mentioned above, the requirements of photolithography for forming micropatterns are increasing. One known method for obtaining finer patterns is to use an exposure having a short wavelength of resist pattern formation.

For example, i-rays (365 nm) emitted from high-pressure mercury lamps have been used in DRAM production with integration levels up to 64 megabits. In the process for mass production of 256 megabit DRAM, KrF excimer laser light (248 nm) is substantially used as exposure instead of i-ray. For use in DRAM production with densities of 1 gigabit or more, exposure with short wavelengths has been studied, and the use of ArF excimer laser light (193 nm), F ₂ excimer laser light (157 nm), X-rays and electron beams is effective. [Tan-hacho Fotorejisuto Zairyo-ULSI Ni Muketa Bisaikako- (Micro-process for short wavelength photoresist material-ULSI), et al., 1988].

In particular, exposure having an ArF excimer laser is considered as a next generation exposure technique. There is an increasing demand for the development of resists with high sensitivity, high resolution and excellent dry etching resistance, and is suitable for exposures with ArF excimer lasers.

Conventional resist materials that are widely used for exposure to i-rays and KrF excimer laser light include resists containing aromatic polymers, thereby obtaining high resistance to delaching. For example, novolak resists and chemically amplified polyvinylphenol resists are known. However, with the aromatics combined for the purpose of providing dry etching resistance, the resist is transmitted substantially free of light in the wavelength region for ArF excimer laser light. Since these conventional resists are difficult to irradiate the bottom layer of the resist film with light, there is a disadvantage that a pattern having a satisfactory cross-sectional shape cannot be obtained.

One known technique for eliminating problems associated with resist transparency is to use aliphatic polymers that do not contain, for example, aromatic rings of poly (methylmethacrylate) (see J. Vac. Sci. Technol , B9, 3357 (1991). However, since the polymer cannot be expected to have sufficient dry etching resistance, it cannot be put to practical use. Thus, the most important problem in developing a resist material for exposure with an ArF excimer laser is to obtain both improved transparency and high resistance to dry etching.

Under these circumstances, it was found that the resists containing alicyclic hydrocarbon groups instead of aromatic rings were the same as the dry etching resistance for resists containing aromatic rings, and the absorption was reduced at 193 nm. SPIE, 1672,66 (1992). This record has been intensively studied with the use of several polymers.

Such attempts have long been made to apply polymers having alicyclic hydrocarbon groups to resists. For example, Japanese Patent Application Laid-Open No. 60-195542 and Japanese Patent Application Laid-open No. 2-59751 describe norbornene polymers, and Japanese Patent Application Laid-Open No. 2-146045 discloses various types having alicyclic hydrocarbon attack and maleic anhydride units. Alkali soluble resins are described.

Japanese Patent Laid-Open No. 5-80515 describes a copolymer of norbornene and an acrylic acid ester protected with an acid-decomposable group. JP-A 4-39665, JP-A 5-265212, JP-A 5-80515, and JP-A 7-234511 disclose copolymers having adamantane skeletons in the side chains. Japanese Patent Laid-Open Nos. 7-252324 and 9-221526 disclose polymerizable compounds in which an alicyclic hydrocarbon group having 7 to 12 carbon atoms including a crosslinked cyclic hydrocarbon group is bonded to the side chain thereof. Examples of the alicyclic hydrocarbon group include tricyclo [5.2.1.02.6] decanedimethylene, tricyclo [5.2.1.02.6] decanediyl, norbornanediyl, norbornanedimethyl and adamantanediyl groups. do. Japanese Patent Laid-Open No. 7-199467 discloses a polymerizable compound having a cyclohexyl group bonded to tricyclodecanyl, dicyclopentenyl, dicyclopentenyloxyethyl, norbornyl, or a side chain thereof.

Japanese Patent Laid-Open No. 9-325498 describes a polymer having a main chain containing cyclohexane and isobornyl skeleton. Japanese Patent Laid-Open No. 9-230595, Japanese Patent Laid-Open No. 9-244247, Japanese Patent Laid-Open No. 10-10739, WO 97-33198, EP 794458 and EP 789278, for example. There is described a polymer having a main chain comprising any of a variety of cycloolefins of dicycloolefin bound thereto. Japanese Patent Application Laid-open No. Hei 8-82925 and Japanese Patent Laid-Open No. Hei 9-230597 describe more preferable compounds having a nerpenoid skeleton having a methyl group or a menthyl derivative group.

In addition, there is a technique of increasing the resolution by adding a low molecular weight dissolution inhibitor. Japanese Patent Application Laid-open No. Hei 8-15865 describes the use of t-butyl ester of astrostan as a dissolution inhibitor, and Japanese Patent Application Laid-open No. Hei 9-265177 describes norbornyl, adamantyl, decanyl or cyclohex. A low molecular weight dissolution inhibitor is described which foams a practical group and an acid-decomposable group bound thereto. The use of t-butylisocholate oligomers as dissolution inhibitors is effective in increasing adhesion and contrast. SPIE, 3049, 84 (1997).

Conventionally, chemically amplified positive resists comprising aromatic polymers for use with KrF excimer lasers are described, for example, in Proc. SPIE, 1672, 46 (1992), Proc. SPIE, 2438, 551 (1995), Proc. SPIE, 2438, 568 (1995), Proc. SPIE, 1925, 14 (1993), J. Photopolym. Sci. Tech., Vol. 8. No. 4, 535 (1995), J. Photopolym. Sci. Tech., Vol. 5, No. 1,207 (1992), J. Photopolym. Sci. Tech., Vol. 8, No. 4, 561 (1995) and Jpn. J.Appl. Phys., 33,7023 (1994) has the same problem as recorded. The fixed period from exposure to heat treatment (PED) is longer, and there is a problem that the acid present on the surface of the acid or the resist that forms the dispersion is made insoluble by basic impurities in the atmosphere. As a result, the resist reduces photosensitivity and, through development, provides a resist pattern with a non-uniform profile and line width.

A known technique for eliminating this problem is the addition of amines to chemically amplified resists comprising aromatic polymers. This technology is disclosed in Japanese Laid-Open Patent Publication No. 63-149640, Japanese Laid-Open Patent Publication 5-249662, Japanese Laid-Open Patent Publication 5-127369, Japanese Laid-Open Patent Publication 5-289322, Japanese Laid-Open Patent Publication 5-249683, Japanese Laid-Open Patent Publication 289340, Japan JP 5-232706, JP-A 5-257282, JP-A 6-242605, JP-A 6-242606, JP-A 6-266100, JP-A 6-266110, JP-A 6-266110 6-6-902, JP 7-120929, JP 7-146558, JP 7-319163, JP 7-508840, JP 7-333844, JP 7-338 -219217, Japanese Patent Laid-Open Publication No. 7-92678, Japanese Patent Laid-Open Publication 7-28247, Japanese Patent Laid-Open Publication 8-22120, Japanese Patent Laid-Open Publication 8-110638, Japanese Patent Laid-Open Publication 8-123030, Japanese Patent Laid-Open Publication 9-274312 Japanese Patent Laid-Open Nos. 9-166871, Japanese Patent Laid-Open No. 9-292708, Japanese Patent Laid-Open No. 9-325496, Japanese Patent Laid-Open No. 7-508840, and US Patent Nos. 5,525,543, 5,629,134 and 5,667,938, etc. Described.

When any of the amine uses described in the above references is added to a chemically amplified resist for exposure to an ArF excimer laser containing a non-aromatic polymer having a main chain comprising an alicyclic hydrocarbon unit, this addition will change the sensitivity. In the case of a resist containing an aromatic polymer, it is effective to obtain a more uniform resist pattern of profile and line width through development. However, the addition of these amines to the resist including alicyclic neutralizers results in extremely poor performance against burn defects. Effective measurement of this is desirable.

The object of the present invention achieved in view of the above problems shows particularly good performance on residual film ratio, resist profile, resolution, and dry etching resistance when exposed to far ultraviolet light, in particular ArF excimer laser light, and problems of development defects. It is to provide a positive photosensitive resin composition that does not bring.

We have intensively studied the materials for chemically amplified positive resist compositions. As a result, the above object is achieved as at least one of a polymer comprising an alicyclic hydrocarbon skeleton having a specific structure, a photoacid generator, a nitrogen-containing basic compound and a fluorine-type surfactant and a silicon-type surfactant.

The present invention includes the following structures.

(1) (A) a compound which generates an acid by irradiation of actinic rays,

(B) a polymer having a partial structure represented by formula (Ia)

(C) a nitrogenous base compound, and

(D) Positive photosensitive resin composition containing at least one of a fluorine-type surfactant and a silicone type surfactant:

Wherein R ₁ to R ₄ are each independently a hydrogen atom, a hydroxyl group, a carboxyl group, an alkyl group, an alkoxy group, a substituted alkyl group, a substituted alkoxy group, or R ₁ and R ₃ or R ₂ and R ₄ are bonded to each other to form a ring. When, cycloalkyl group is represented;

X represents a divalent organic group having 2 to 20 carbon atoms;

R ₅ represents a hydrogen atom, an alkyl group, a substituted alkyl group, a cycloalkyl group, a substituted cycloalkyl group, or a group decomposed by the action of an acid, wherein the group having a -COOR ₅ function;

z represents a group of atoms forming a cyclohexane or decalin ring bonded to a carbon atom.

(2) The positive photosensitive resin composition according to the above (1), wherein the polymer (B) has a group decomposed by the action of an acid.

(3) The positive of the above (1), comprising a low molecular acid degradable dissolution inhibiting compound having at least one group decomposable by the action of an acid and having a molecular weight of 2,000 or less which has an increased alkali solubility by the action of an acid. Photosensitive resin composition.

(4) The positive photosensitive resin composition according to the above (1) to (3), wherein the actinic radiation is far ultraviolet rays having a wavelength of 220 nm or less.

The inventors have done an intensive study of the constituents for chemically amplified positive resist compositions. As a result, this object has been achieved by using a polymer comprising a specific alicyclic hydrocarbon backbone structure, a photoacid generator, a nitrogen-containing basic compound, and a combination of at least one of a fluorinated surfactant and a silicon type surfactant.

The present invention further includes the following configurations.

(5) a compound which generates an acid by (A) actinic radiation,

(B) a polymer having a partial structure represented by formula (Ib),

(C) a nitrogenous base compound, and

(D) A positive photosensitive resin composition comprising at least one of a fluorine type surfactant and a silicone type surfactant:

Wherein R ₁ to R ₄ independently represent a hydrogen atom, a hydroxyl group, a carboxyl group, an alkyl group, an alkoxy group, a substituted alkyl group, a substituted alkoxy group, or R ₁ and R ₃ or R ₂ and R ₄ are bonded to each other to form a ring. When, cycloalkyl group is represented;

X represents a divalent organic group having 2 to 20 carbon atoms;

R ₅ is a hydrogen atom, an alkyl group, a substituted alkyl group, a cycloalkyl group, a substituted cycloalkyl group or a group decomposed by the action of an acid, and represents the group having the function of —COOR ₅ ;

Z represents a group of atoms forming a cyclohexane or decalin ring bonded to a carbon atom).

(6) The positive photosensitive resin composition according to the above (5), wherein the polymer (B) has a group decomposed by the action of an acid.

(7) The low molecular acid-decomposable dissolution inhibiting compound according to the above (5) or (6), having one or more groups decomposable by the action of an acid and having a molecular weight of 2,000 or less, which has an increased alkali solubility by the action of an acid. Positive photosensitive resin composition comprising a.

(8) The positive photosensitive resin composition according to any one of (5) to (7), wherein the actinic ray is far ultraviolet rays having a wavelength of 220 nm or less.

The inventors have intensively studied the components for chemically amplified positive resist compositions. As a result, it has been found that the above object is achieved by using a polymer composed of a specific alicyclic hydrocarbon backbone structure, a photoacid generator, a nitrogen-containing base compound, and a combination of at least one fluorine-type surfactant and silicon-type surfactant. The present invention further includes the following configurations.

(9) (A) a compound which generates an acid by irradiation of actinic rays,

(B) a polymer having a partial structure represented by the following formula (Ic),

(C) a nitrogenous base compound, and

(D) at least one fluorine type surfactant and silicone type surfactant:

(Wherein R ₁ to R ₄ are each a hydrogen atom, a hydroxyl group, a carboxy group, an alkyl group, an alkoxy group, a substituted alkyl group, a substituted alkoxy group or when R ₁ and R ₃ or R ₂ and R ₄ are bonded to each other to form a ring, A cycloalkyl group;

X represents a monovalent organic group having 2 to 20 carbon atoms;

R ₅ represents the group which acts as a hydrogen atom, an alkyl group, a substituted alkyl group, a cycloalkyl group, a substituted cycloalkyl group or a group in which -COOR ₅ is decomposed by the action of an acid;

Y represents the following:

Wherein R ₆ and R ₇ independently represent a hydrogen atom or a methyl group, and n represents 1 or 2.), a positive photosensitive resin composition comprising:

(10) In the positive photosensitive resin composition according to the above (9), the polymer (B) has a group decomposed by the action of an acid.

(11) The above (9) or (10) comprising a low molecular, acid decomposable, dissolution inhibiting compound having at least one degradable group by the action of an acid and having a molecular weight of 2,000 or less which increases alkali solubility by the action of an acid. The positive photosensitive resin composition described.

(12) The positive photosensitive resin composition according to any one of (9) to (11), wherein the actinic radiation has a wavelength of 220 nm or less.

The inventors have intensively studied the materials for chemically amplified resist compositions. As a result, it has been found that this object is achieved by using a polymer comprising a specific alicyclic hydrocarbon backbone, a photoacid generator, a nitrogen-containing base compound and a combination of at least one fluorine-type surfactant with a silicone-type surfactant. The invention further includes the following structures.

(13) (A) a compound which generates an acid by irradiation of actinic rays,

(B) a polymer having a partial structure represented by the following general formula (Id),

(C) nitrogen-containing basic compounds, and

(D) a positive photosensitive resin composition comprising at least one fluorine type surfactant and a silicone type surfactant:

Wherein R ₁ represents a methyl group or an ethyl group; R ₁₂ and R ₁₃ each independently represent a hydroxy group, a carboxy group, an alkyl group, an alkoxy group, a substituted alkyl group, a substituted alkoxy group, or R ₁₂ and R ₁₃ combine with each other to form a ring. When used, a cycloalkyl group; X ₁ represents a divalent organic group having 2 to 20 carbon atoms; R ₁₄ represents a hydrogen atom, an alkyl group, a substituted alkyl group, a cycloalkyl group, a substituted cycloalkyl group, or a -COOR ₁₄ valent acid To a group which acts as a group which is decomposed by the action).

(14) In the positive photosensitive resin composition according to the above (13), the polymer (B) has a group which is decomposed by the action of an acid.

(15) to (13) or (14) comprising a low molecular, acid decomposable, dissolution inhibiting compound having at least one degradable group by the action of an acid and having a molecular weight of 2,000 or less which increases alkali solubility by the action of an acid. The positive photosensitive resin composition described.

(16) In the positive photosensitive resin composition according to any one of (13) to (15), actinic radiation is far ultraviolet rays having a wavelength of 220 nm or less.

Compounds for use in the present invention are described in detail below.

First, the polymer (B) which has a structure shown by general formula (Ia) is demonstrated.

The alkyl group represented by R ₁ to R ₄ in formula (Ia) includes a linear or branched alkyl group having 1 to 10 carbon atoms which may be substituted. Specific examples thereof include methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl, hydroxymethyl, hydroxyethyl, norbornylmethyl and adamantylmethyl. Examples of the alkoxy group represented by R ₁ to R ₄ include an alkoxy group having 1 to 10 carbon atoms, and may have one or more substituents. Specific examples thereof include methoxy, ethoxy, propyl, n-butyl, hydroxymethyl, hydroxyethyl, norbornylmethyl and adamantylmethyl. Examples of the alkoxy group represented by R ₁ to R ₄ include an alkoxy group having 1 to 10 carbon atoms, and may have one or more substituents. Specific examples thereof include methoxy, ethoxy, n-butoxy, t-butoxy, propoxy and isopropoxy.

Examples of the substituent for the group include a halogen atom, a cyano group and a nitro group. Examples of the alkyl group and substituted alkyl group represented by R ₅ are the same as those listed above for R ₁ to R ₄ . Examples of the cycloalkyl group represented by R ₅ are cycloalkyl groups having 4 to 20 carbon atoms such as cyclopentyl, cyclohexyl, adamantyl, norbornyl, tricyclodecanyl, tetracyclododecanyl and tricyclopentyl Examples of substituents for these cycloalkyl groups include hydroxy groups, halogen atoms, carboxy and alkoxy groups having 1 to 4 carbon atoms.

Examples of the ring formed by R ₁ and R ₃ bonded to each other or R ₂ and R ₄ bonded to each other include a ring in which linked R ₁ and R ₃ or linked R ₂ and R ₄ constitute any of the following groups.

-C (= O) -O-C (= O)-

-C (= O) -NH-C (= O)-

-CH ₂ -C (= O) -OC (= O)-

When -COOR ₅ represents a group which is decomposed by the action of an acid, examples of R ₅ include 2-20 hydrocarbon groups (e.g. t-butyl, norbornyl and cyclodecanyl), tetrahydrofuranyl, Alkoxy ethyl groups, such as tetrahydropyranyl, ethoxyethyl, and isopropylethyl, lactone groups, and cyclohexyloxyethyl are included.

Examples of the divalent organic group having 2 to 20 carbon atoms represented by X include 4 to 20 carbon atoms such as alkylene group having 2 to 20 carbon atoms such as ethylene and propylene, cyclobutylene and cyclohexylene, etc. The branch includes an arylene group having 6 to 20 carbon atoms such as a cycloalkylene group, phenylene and a divalent cycloolefin group which may be crosslinked.

The partial structure represented by the formula (I) may be included in the main chain of the polymer or in the side chain thereof. In the present invention, the partial structure is preferably included in the main chain of the polymer.

Examples of the polymer having each repeating unit including the substructure represented by the formula (Ia) include polymers represented by the following formulas (a-1) to (a-24).

In one example of the process for synthesizing the polymer, dicyclopentadiene is first polymerized with a phenolic compound to synthesize a polymer having a structural unit represented by the following formula (II), which is hydrolyzed to form To obtain a polymer. The polymer represented by the general formula (III) is esterified with a carboxylic anhydride represented by the following general formula (IV) to obtain a polymer represented by the following general formula (V).

The polymer represented by the formula (V) is further esterified with the provided units to obtain an esterified polymer represented by any of (a-1) to (a-24).

(In the formula, Z represents a divalent organic group, and R ₁ to R ₄ have the same meaning as in formula (Ia).)

The synthesis process will be described in more detail below.

Examples of the polymer represented by the formula (II) include Japanese Patent Application Laid-Open No. 60-104830, Japanese Patent Application Laid-Open 62-4720, Japanese Patent Application Laid-Open 62-104830, Japanese Patent Application Laid-Open 63-99224, and Japanese Patent Application Laid-Open No. 4- 300916, Japanese Patent Application Laid-Open No. 4-164919, Japanese Patent Application Laid-Open No. 4-168122, Japanese Patent Application Laid-Open No. 4-170423, Japanese Patent Application Laid-Open No. 4-170424, Japanese Patent Application Laid-Open No. 4-222819 and Japanese Patent Application Laid-Open No. 4-339820 Synthesized as described, the dicyclopentadiene is reacted with the phenolic compound in the molten state or in a suitable solvent. Examples of solvents include benzene, toluene and xylene. This polymerization is performed by dropwise addition of Lewis acid to the mixture of dicyclopentadiene and phenolic compound, or by adding dropwise addition of dicyclopentadiene to the mixture of phenolic compound and Lewis acid. Dropping addition is carried out for several minutes to several hours. After addition, the reaction mixture may be further reacted for several hours. The reaction temperature for this polymerization is generally 20 to 180 ° C, preferably 60 to 120 ° C.

In order to obtain the polymer represented by general formula (III) by hydrogenating the polymer represented by general formula (II), a well-known method can be used. For example, the polymer represented by formula (II) was dissolved in a solvent, and the solution was extracted by contacting with hydrogen under a metal catalyst. The solvent is preferably one which dissolves the polymer represented by the formula (II), is stable to hydrogenation, and can be easily removed. Preferable examples thereof include low alcohols such as methanol, ethanol, propanol and butanol, low ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, and cyclic ethers such as tetrahydrofuran and dioxane. Moreover, phenols, such as cresol, are preferable. Particularly preferred among these solvents is low alcohols. Preferred examples of metal catalysts include nickel, cobalt, palladium, pratium and rhodium. The catalytic metal may be used after or fixed to the metal oxide support. In general, nickel and cobalt may be used alone or in a form of Raney or after fixing to a porous support such as silica, alumina, carbon, or diatomaceous earth.

Precious metals are generally used in the form of oxides or after they are fixed to a support. Although the usage-amount of a catalyst varies with the kind of catalyst, its suitable range is generally as follows. Hydrogenation may be carried out as an intermittent treatment of autoclaving or as a continuous treatment of passing the reaction mixture through a fixed bed. In the case of intermittent treatment, a suitable range of catalyst amounts is about 0.01 to 10% by weight of metal based on the treated polymer. In the case of a continuous flow process, a suitable range of catalyst amounts is one wherein the WHSV of the catalyst based polymer is about 10 kg / kg.hr.

In the case of a continuous flow process, a catalyst fixed to the support is generally used. The temperature for hydrogenation is generally 50 to 300 ° C., preferably 150 to 250 ° C. The hydrogen pressure is generally 10 to 200 kg / cm 2, preferably 50 to 100 kg / cm 2, in view of the reaction temperature, resistance pressure of the apparatus, and the like. Preferred treatment periods may be selected depending on, for example, the type and amount of catalyst used, the conditions for the treatment of the treatment temperature and the nature of the treated polymer.

In the present invention, the degree of hydrogenation of the aromatic nucleus is preferably at least 60%, more preferably at least 70%, most preferably at least 80%. A degree of nuclear hydrogenation of less than 60% is undesirable because it results in increased light absorption at 193 nm and increased damaged resist profile.

The method for obtaining the polymer represented by the formula (V) is described below. The polymer represented by the formula (V) is obtained by esterifying the polymer represented by the formula (III) and the carboxylic anhydride represented by the formula (IV).

Examples of carboxylic acid anhydrides used for esterification include maleic anhydride, succinic anhydride, itaconic anhydride, phthalic anhydride, citraconic anhydride, α-methylglutaconic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, Chloromaleic anhydride, d-phenylmaleic anhydride, pyromellitic dianhydride, hyminic anhydride, 2,6-endomethylene phthalic anhydride, terpene / maleic anhydride products, α-terpinene / maleic anhydride products, 4 , 5-cyclohexanedicarboxylic acid anhydride, 1-methyl-4,5-cyclohexanedicarboxylic acid anhydride, 1-methyl-4,5-cyclohexanedicarboxylic acid anhydride, 3,6-methylene-1 , 2,3,6-tetrahydro-cis-phthalic anhydride, (4-carboxy-4-cyclohexenyl) acetic anhydride, 4-methyl-4,5, -cyclohexenedicarboxylic acid anhydride, (4-carboxy -5-cyclohexenyl) acetic anhydride, 3,6-methylene-1,2,3,6-tetrahydro-cis-phthalic anhydride, 6- (5-carboxybicyclo [2.2.1] hept-2-enyl) acetic anhydride, 3, 6-methano-1-methyl-1, 2, 3, 6-tetrahydro-cis-phthalic anhydride, 2 Oxa-1,4-dioxo-5, 8-methano-1, 2, 3, 4, 4a, 5, 8, 8a-octahydronaphthalene, 5,8-methano-1, 2, 3, 4, 4a, 5, 8, 8a-octahydronaphthalene-1,2-dicarboxylic acid anhydride, 5,8-methano-1-methyl-1, 2, 3, 4, 4a, 5, 8, 8a Octahydronaphthalene-2,3-dicarboxylic acid anhydride, 1, 4, 5, 8-dimethano-1, 2, 3, 4, 4a, 5, 8, 8a-octahydronaphthalene-2,3 -Dicarboxylic acid anhydride, 2-oxo-1,3-dioxo-1, 2, 3, 4, 4a, 5, 8, 8a, 9,9a, 10, 10a-dodecahydroanthracene, 4- ( 5-bicyclo [2.2.1] -hept-2-enyl) phthalic anhydride, phenolphthalein, 4- (2,5-dioxotetrahydrofuran-3-yl) tetraline-1,2-dicarboxylic acid Anhydride, 5- (2,5-dioxotetrahydrofuranyl) -3-methyl-3-cyclohexene- 1,2-dicarboxylic acid anhydride, 4-methylcyclohexene-1,2-dicarboxylic acid anhydride , Methylcyclohexene-1,2-dicarboxylic acid anhydride and endo-dicyclo [2.2.2] oct-5-ene-2,3-dicarboxylic acid anhydride.

The carboxylic acid anhydrides may be used alone or in combination of two or more thereof.

The esterification reaction is described, for example, in R. P. Hanzilik, Org. Synth., VI, 560 (1988) or J. Cason, Org. By the method described in Synth., III, 169 (1955), the target polymer can be easily obtained. Specifically, the polymer represented by the formula (III) is dissolved in a solvent together with the carboxylic anhydride represented by the formula (IV), and the products are reacted with each other in the presence of a catalyst at a temperature of 5 to 150 ° C to obtain a target polymer. Examples of solvents used herein include benzene, toluene, xylene, DMF and THF. Catalysts include, for example, basic catalysts comprising pyridine, sodium acetate, 4-dimethylaminopyridine and triethylamine.

In the esterification reaction, the polymer represented by the general formula (III) and the carboxylic acid anhydride represented by the general formula (IV) range from 0.5 to 1.0 mole of the polymer of which the amount of the carboxylic acid anhydride represented by the general formula (IV) is represented by the general formula (III). Molar concentration of 2.0 moles. The occupied amount of the carboxylic acid anhydride of 0.5 mol or less per mole of polymer is undesirable because the resulting product polymer, represented by the formula (V), has insufficient alkali solubility, resulting in a resist having reduced sensitivity or reduced resolution. . On the other hand, when the amount of carboxylic acid anhydride occupied exceeds 2.0 mol per polymer, the acid anhydride forms diester through alcohol decomposition. As a result, the polymer represented by the formula (V) tends to have insufficient alkali solubility and provides a resist with reduced sensitivity. Thus, by controlling the reaction, it is preferable that the acid anhydride form the half ester through alcohol decomposition.

This positive photoresist composition included in the present invention is a polymer represented by formula (V) (a polymer having a partial structure represented by formula (Ia) but not including an acid-decomposable group), an acid-decomposable dissolving inhibitor, and a photoacid generator It may include. However, it is preferable to mix the acid-decomposable group with the polymer represented by the formula (V). That is, the polymer having the partial structure represented by the formula (Ia) preferably includes an acid-decomposable group.

The acid-decomposable group may be combined with the polymer represented by the formula (V) by protecting the carboxyl group of the polymer through esterification. Examples of this esterification reaction include a method in which the polymer represented by formula (V) is esterified with tertiary alcohol with 4-dimethylaminopyridine (DMAP) or the like (G. Hoefle, W. Steglich and Vorbrueggen, Angew. Chem. Int. Ed. Engle., 17, 569 (1978)), methods using trifluoroacetic anhydride (RC Parish and LMStock, J. Org. Chem., 30, 927 (1965)), and DCC (dicyclohexyl) Carbodiimide) (B. Neises and W. Steglich, Org. Synth., 63, 183 (1985)).

Furthermore, a method may be employed including converting the carboxy of the polymer represented by the formula (V) to carbonyl chloride having SOCl ₂ or the like and reacting with an alcohol or a metal alkoxide to form an ester. It is possible to use the DCC-DMAP method.

Second, the polymer (B) having a structure represented by the formula (Ib) is described below.

In formula (Ib), R ₁ to R ₅ , X and Z have the same meaning as in formula (Ia). In formula (Ib), the substituents or groups represented by R ₁ to R ₅ , X and Z may be the same or different.

The partial structure represented by general formula (Ib) may be contained in the main chain or the side chain thereof. In the present invention, the partial structure is preferably included in the main chain of the polymer.

Examples of the polymer having a repeating unit each containing a substructure represented by the formula (Ib) include the following polymers (a-1b) to (a-13b).

One example of a process for synthesizing these polymers includes the method described in Japanese Patent Laid-Open No. 7-306532. In this method, dicyclopentadiene is first polymerized with a phenolic compound to synthesize a polymer having a structural unit represented by the formula (IIb), condensation of the remaining phenolic compound with an aldehyde, and a polymer represented by the following formula (IIIb) Get The polymer represented by the general formula (IIIb) is hydrogenated to obtain a polymer represented by the following general formula (IVb). The polymer represented by the formula (IVb) is esterified with the carboxylic anhydride represented by the formula (Vb) to obtain the polymer represented by the formula (VIb).

By esterifying the polymer represented by the formula (VIb) with the units provided as necessary, the exemplified polymers represented by any of (a-1b) to (a-13b) are obtained.

(In the formula, Z ₁ represents a divalent organic group, R ₁ to R ₄ have the same meanings as R ₁ to R ₄ of formula (Ⅰb).)

The synthesis process will be described in more detail below. Examples of the polymer represented by the formula (IIb) include Japanese Patent Application Laid-Open No. 60-104830, Japanese Patent Application Laid-Open 62-4720, Japanese Patent Application Laid-Open 62-104830, Japanese Patent Application Laid-Open 63-99224, and Japanese Patent Application Laid-Open No. 4- 300916, Japanese Patent Application Laid-Open No. 4-164919, Japanese Patent Application Laid-Open No. 4-168122, Japanese Patent Application Laid-Open No. 4-170423, Japanese Patent Application Laid-Open No. 4-170424, Japanese Patent Application Laid-Open No. 4-222819 and Japanese Patent Application Laid-Open No. 4-339820 Synthesized as described, dicyclopentadiene is reacted with phenolic compounds in molten state or in a suitable solvent. Examples of solvents include benzene, toluene and xylene. This polymerization may be carried out by dropwise addition of Lewis acid to a mixture of dicyclopentadiene and phenolic compound, or by adding dropwise addition of dicyclopentadiene to a mixture of phenolic compound and Lewis acid. Dropping addition may be performed for several minutes to several hours. After addition, the reaction mixture may be further reacted for several hours. The reaction temperature for this polymerization is generally 20 to 180 ° C, preferably 60 to 120 ° C.

After the first step, the synthesis of the polymer represented by the formula (IIIb), ie the condensation of the residual phenolic compound with the aldehyde as the second step, can be carried out continuously. These reaction products are reacted in the molten state or in a suitable solvent. A solvent may be added freshly to this reaction. Moreover, examples of the solvents mentioned above include methanol, ethanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, and tetrahydrofuran. A small amount of water may be added at this stage to decompose the Lewis acid. Acid catalysts, such as Lewis acid, hydrochloric acid, phosphoric acid, or oxalic acid, can be newly added.

Aldehydes may be paraformic acid aldehyde, aqueous solution of formaldehyde, or the like. When using paraformaldehyde, its solution in a solvent may be added dropwise, or aldehyde in a solid state may be added to two or more portions. When using a water-soluble formaldehyde solution, it may be added dropwise for several minutes to several hours. This reaction may be performed at a temperature in the same range as the first stage reaction or at a different temperature.

Subsequently, the phenolic compound remaining unreacted is removed from the reaction mixture by vacuum distillation, and the residue is diluted to the concentration provided as solvent. The resulting solution is washed with ion-exchanged water to mainly remove ions. Thus, the solvent used for reaction and washing is removed by vacuum distillation to cool the residue to obtain a solid. Thus, a modified phenolic resin can be obtained.

In order to obtain the polymer represented by general formula (IV) by hydrogenating the polymer represented by general formula (IIIb), a well-known method can be used. For example, the polymer represented by formula (IIIb) was dissolved in a solvent and extracted by contacting this solution with hydrogen in the presence of a metal catalyst. It is preferred that the solvent is stable for dissolving and hydrogenating the polymer represented by the formula (IIIb) and can be easily removed after hydrogenation. Preferable examples thereof include low alcohols such as methanol, ethanol, propanol and butanol, low ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, and cyclic ethers such as tetrahydrofuran and dioxane. Further preferred are phenols such as cresols. Particularly preferred among these solvents is low alcohols.

Preferred examples of metal catalysts include nickel, cobalt., Palladium, platinum and rhodium. The catalyst metal may be used after being fixed to or fixed to a metal oxide support. In general, nickel and cobalt are each used after being fixed to a Raney type or a porous support such as silica, alumina, carbon, or diatomaceous earth.

Precious metals are generally used in the form of oxides or after they are fixed to a support. Although the usage-amount of a catalyst varies with the kind of catalyst, its suitable range is generally as follows. Hydrogenation may be carried out as an intermittent treatment of autoclaving or as a continuous treatment of the reaction mixture through a fixed bed. In the case of intermittent treatment, a suitable range of catalyst amounts is about 0.01 to 10% by weight of metal based on the treated polymer. In the case of a continuous flow process, a suitable range of catalyst amounts is about 0.1 to 10 kg / kg.hr of WHSV of the catalyst based polymer. In the case of a continuous flow process, a catalyst fixed to the support is generally used. The temperature for hydrogenation is generally from 50 to 300 ° C, preferably from 150 to 250 ° C, in view of the reaction temperature, the resistance pressure of the apparatus and the like. The desired treatment period can be selected depending on, for example, the type and amount of catalyst used, the conditions for treatment of the treatment temperature, the nature of the treated polymer, and the like.

In the present invention, the degree of hydrogenation of the aromatic nucleus is preferably at least 60%, more preferably at least 70%, most preferably at least 80%. The degree of hydrogenation of the nuclei of 60% or less is undesirable because it results in an increase in light absorption at 193 nm and an increase in damaged resist profile.

The method for obtaining the polymer represented by the formula (VIb) is described next. The polymer represented by the formula (VIb) is obtained by esterifying the polymer represented by the formula (IVb) with the carboxylic anhydride represented by the formula (Vb).

Examples of the carboxylic anhydrides used for the esterification are the same as those listed above.

The esterification reaction is described, for example, in R. P. Hanzilik, Org. Synth., VI, 560 (1988) or J. Cason, Org. By carrying out by the method described in Synth., III, 169 (1955), the target polymer can be easily obtained. In particular, the polymer represented by the formula (IVb) is dissolved in a solvent together with the carboxylic anhydride represented by the formula (Vb), and the reaction products are reacted with each other in the presence of a catalyst at a temperature of 5 to 150 ° C to obtain a target polymer. Examples of solvents used here include benzene, toluene, xylene, DMF and THF. The catalyst may be a base catalyst and includes, for example, pyridine, sodium acetate, 4-dimethylaminepyridine and triethylamine.

In the esterification reaction, the amount of the carboxylic acid anhydride represented by the general formula (IVb) and the carboxylic acid anhydride represented by the general formula (Vb) is 0.5 to 1.0 mol of the polymer represented by the general formula (IVb). Preferably at a molar concentration of 2.0 moles. The occupied amount of carboxylic acid anhydride of 0.5 moles or less per mole of polymer is undesirable because the resulting polymer represented by formula (VIb) provides a resist with poor alkali solubility resulting in a reduced sensitivity or reduced resolution. not. On the other hand, when the amount of carboxylic acid anhydride occupied exceeds 2.0 mol per polymer, the acid anhydride forms diester through alcohol decomposition. As a result, the polymer represented by the formula (VI) has a poor alkali solubility and provides a resist having a reduced sensitivity. Therefore, it is preferable to control the reaction so that the acid anhydride forms half ester through alcohol decomposition.

This positive photoresist composition included in the present invention may contain a polymer represented by the formula (VIb) (polymer (B) not containing an acid-decomposable group), an acid-decomposable dissolving inhibitor and a photoacid generator.

However, it is preferable to combine the acid-decomposable group with a polymer represented by the formula (VIb) (a polymer having a partial structure represented by the formula (Ib)).

The acid-decomposable group may be bonded to the polymer represented by the formula (VIb) by protecting the carboxyl group of the polymerized product through esterification. Examples of this esterification reaction include the same method as described above.

Third, the polymer (B) having a structure represented by the formula (Ic) is described below.

In formula (Ic), R ₁ to R ₅ , X and Z have the same meanings as in formula (Ia).

The partial structure represented by general formula (Ic) may be included in the main chain or the side chain thereof.

In the present invention, the partial structure is preferably included in the main chain of the polymer.

Examples of the polymer having a partial structure represented by the formula (Ic) include polymers represented by the following (a-1c) to (a-24c).

One example of a process for synthesizing a polymer having a partial structure represented by the formula (Ic) is the method described in Japanese Patent Laid-Open No. 5-163328. In this method, 4-vinylcyclohexene and / or 5-vinylnorbornene are first polymerized with a phenol compound to synthesize a polymer having a structural unit represented by the following formula (IIc), which is hydrogenated to form a polymer The polymer represented by (IIIc) is obtained. The polymer represented by the formula (IIIc) is esterified with a carboxylic acid anhydride by the following formula to obtain a polymer represented by the following formula (Vc).

The polymer represented by the formula (Vc) is further esterified to the supplied unit as necessary, thereby obtaining the exemplified polymer represented by any one of (a-1c) to (a-24c).

(Wherein Z ₀ represents-(CH ₂ ) _m- ; R ₆ and R ₇ each represent a hydrogen atom or a methyl group; m represents 0 or 1; n represents 1 or 2; Z ₁ Represents a divalent organic group; R ₁ to R ₄ have the same meaning as in formula (Ic).).

The synthesis process will be described in more detail. The polymer represented by formula (II) is readily obtained by reacting 4-vinylhexene and / or 5-vinylnorbornene with a phenolic compound in the presence of an acid catalyst. Examples of phenolic compounds include phenol, o-cresol, m-cresol, p-cresol, t-butylphenol, cyclohexylphenol, p-cumylphenol, xylenols and naphthols.

In the reaction of 4-vinylcyclohexene and / or 5-vinylnorbornene with a phenolic compound, the reaction product preferably contains an amount of phenolic compound relative to 4-vinylcyclohexene and / or 5-vinylnorbornene from 0.8 to 12 equimoles, more preferably 2-10 moles. The charge amount of the phenol compound of 0.8 equimolar or less is not preferable because it is difficult to obtain a polymer having a desired molecular weight. Its undesired amounts exceeding 12 equimoles are undesirable because they require a lot of effort to remove phenolic compounds that remain unreacted.

Preferred examples of the acid catalyst which use 4-vinylcyclohexene and / or 5-vinylnorbornene for reacting with a phenol compound include boron trifluoride; Boron trifluoride, such as a mixture, an ether mixture, and an alcohol mixture of boron trifluoride; Aluminum compounds such as aluminum trichloride and diethylammonium monochloride; Iron chloride; Titanium tetrachloride; Sulfuric acid, hydrogen fluoride; And trifluoromethanesulfonic acid. Particularly preferred in view of catalytic activity and catalyst removal convenience are boron trifluoride, boron trifluoride / ether mixtures, boron trifluoride / phenol mixtures, boron trifluoride / water mixtures, boron trifluoride / alcohol mixtures, and Boron fluoride / amine mixture. Most preferred of these are boron fluoride and trifluoride / phenol mixtures. The acid catalyst is used in different amounts. For example, the boron trifluoride / phenol mixture is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight per 100 parts by weight of 4-vinylcyclohexene and / or 5-vinylnorbornene.

The reaction can be made with or without solvent. If no solvent is used, the phenolic compound accounts for at least 1 equivalent, more preferably 3 to 10 equivalents relative to 4-vinylcyclohexene and / or 5-vinylnorbornene. In the case of using a solvent, the solvent is not particularly limited as long as it does not inhibit the reaction. Preferred examples thereof include aromatic hydrocarbon compounds such as benzene, toluene and xylene. The reaction temperature varies depending on the type of acid catalyst used. For example, in the case of using a boron trifluoride / phenol mixture, the reaction is preferably performed at a temperature of 20 to 170 ° C, more preferably 40 to 150 ° C. Reaction temperatures exceeding 170 ° C. are undesirable because they cause catalysis or side effects. The reaction temperature of 20 ° C. or lower is economically disadvantageous because the low temperature delays the reaction, which is not preferable.

The reaction may be carried out by gradually adding 4-vinylcyclohexene and / or 5-vinylnorbornene. This method is effective for preventing 4-vinylcyclohexene and / or 5-vinylnorbornene from isopolymerization.

After completion of the reaction, the catalyst is filtered or inactivated, and the solution thus obtained is concentrated to obtain a polymer represented by the formula (IIc). Methods for catalyst removal vary with the type of accumulator used. For example, in the case of using a boron trifluoro / phenol mixture, a preferred method is to add calcium hydroxide, magnesium hydroxide and the like in an amount of 1 to 10 times the catalytic amount as moles to deactivate the catalyst and filter the catalyst. It involves doing. In filtration, it is desirable to improve the efficiency of the filtration by adding or heating a solvent and otherwise treating the reaction mixture.

In order to hydrogenate the polymer represented by general formula (IIc), and to obtain the polymer represented by general formula (IIIc), a well-known method can be used. For example, the polymer represented by formula (IIc) is dissolved in a solvent, and this solution is extracted in contact with hydrogen in the presence of a metal catalyst.

It is preferable that the solvent dissolves the polymer represented by the formula (IIc), is stable to hydrogenation, and can be easily removed after hydrogenation. Preferable examples thereof include low alcohols such as methanol, ethanol, propanol and butanol, low ketones such as ketone, methyl ethyl ketone, and methyl isobutyl ketone, and cyclic ethers such as tetrahydrofuran and dioxane. Moreover, phenols, such as cresols, are preferable. Particularly preferred among these solvents is low alcohols.

Preferred examples of metal catalysts include nickel, cobalt, palladium, platinum and rhodium. The catalyst metal may be used after being fixed to or fixed to a metal oxide support. In general, nickel and cobalt are each used either alone or after being fixed to a porous support such as silica, alumina, carbon or diatomaceous earth. Precious metals are generally used in the form of oxides or after they are fixed to a support. Although the amount of the catalyst used varies depending on the type of catalyst, its suitable range is generally as follows. Hydrogenation may be carried out as an intermittent treatment of autoclaving or as a continuous treatment of the reaction mixture through a fixed bed.

In the case of intermittent treatment, a suitable range of catalyst amounts is from about 0.01% to 10% by weight of metal based on the treated polymer. In the case of a continuous flow process, a suitable range of catalyst amounts is that the WHSV of the catalyst based polymer is about 0.1-10 kg / kg.hr. In a continuous flow process, a catalyst fixed to the support is generally used. The temperature for hydrogenation is generally 50 to 300 ° C., preferably 150 to 250 ° C. The pressure of hydrogen is generally 10 to 200 kg / cm 2, preferably 50 to 100 kg / cm 2 from the viewpoint of the reaction temperature, the resistance pressure of the apparatus, and the like. The desired treatment period can be chosen depending on, for example, the type and amount of catalyst used, the conditions for the treatment of the treatment temperature and the nature of the treated polymer. In the case of the present invention, the hydrogenation degree of the aromatic nucleus is preferably at least 60%, more preferably at least 70%, most preferably at least 80%. Hydrogenation of less than 60% is undesirable because it results in increased light absorption at 193 nm and an increased damaged resist profile.

The method for obtaining the polymer represented by the formula (Vc) is described next. The polymer represented by the formula (Vc) is obtained by esterifying the polymer represented by the formula (IIIc) with the carboxylic anhydride represented by the formula (IVc).

Examples of carboxylic anhydrides used for esterification are the same as those listed above.

The esterification reaction is described, for example, in R. P. Hanzilik, Org. Synth., VI, 560 (1988) or J. Cason, Org. By carrying out the method described in Synth., III, 169 (1955), the target polymer is easily obtained. Specifically, the polymer represented by the formula (IIIc) is dissolved in a solvent together with the carboxylic anhydride represented by the formula (IVc), and the reaction products are reacted with each other in the presence of a catalyst at a temperature of 5 to 150 ° C to obtain a target polymer. Examples of solvents used here include benzene, toluene, xylene, DMF and THF. The catalyst may be, for example, a base catalyst of pyridine, sodium acetate, 4-dimethylaminopyridine and triethylamine.

In the esterification reaction, the polymer represented by the formula (IIIc) and the carboxylic acid anhydride represented by the formula (IVc) are 0.5 to 1.0 mole of the molar amount of the carboxylic acid anhydride represented by the formula (IVc). Preferably at a concentration of 2.0 mol. The occupied amount of carboxylic acid anhydride of 0.5 mol or less per mole of polymer is undesirable since the resulting polymer represented by formula (Vc) has insufficient alkali solubility resulting in reduced sensitivity or reduced resolution. On the other hand, when the amount of carboxylic acid anhydride occupied exceeds 2.0 mol per polymer, the acid anhydride forms diester through alcohol decomposition. As a result, the polymer represented by the formula (Vc) tends to provide a resist having insufficient alkali solubility and having a reduced sensitivity. Therefore, it is preferable that the acid anhydride be controlled to form half ester through alcohol decomposition.

The positive photoresist composition included in the present invention includes a polymer represented by formula (Vc) (a polymer having a partial structure represented by formula (Ic) but not containing an acid-decomposable group), an acid-decomposable dissolving inhibitor, and a co-generating agent. You may also do it. However, it is preferable to mix an acid-decomposable group with a polymer represented by the formula (Vc) (a polymer having a structural unit represented by the formula (Ic)).

The acid-decomposable group is bonded with the polymer represented by the formula (Vc) by protecting the carboxyl group of the polymer through esterification. Examples of this esterification reaction include a method in which the polymer represented by the formula (Vc) esterifies 4-dimethylaminopyridine (DMAP) or the like with tertiary alcohol (G. Hoefle, W. Steglich and Vorbrueggen, Angew. Chem. Int. Ed. Engle., 17, 569 (1978)), methods using trifluoroacetic anhydride (RCParish and LMStock, J. Org. Chem., 30, 927 (1965)), and DCC (dicyclohexyl) Carbodiimide) (B. Neises and W. Sreglich, Org. Synth., 63, 183 (1985)).

Furthermore, a method comprising converting the carboxy group of the polymer represented by the formula (Vc) to carbonyl chloride having SOCl2 or the like and reacting carbonyl chloride with an alcohol or a metal alkoxide to form an ester may be used. DCC-DMAP method can be used.

Fourth, the polymer (B) having a structure represented by the formula (Id) is described below.

A polymer (B) having a structure represented by formula (Id) for use in the present invention is described below.

Examples of the alkyl group represented by R ₁₂ and R ₁₃ in formula (Id) include linear or cyclic alkyl groups having 1 to 10 carbon atoms which may be substituted. Specific examples thereof include methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl, hydroxymethyl, and hydroxyethyl. Examples of cycloalkyl groups represented by R ₁₂ and R ₁₃ include cyclopentyl and cyclohexyl.

Examples of the alkoxy group represented by R ₁₂ and R ₁₃ include an alkoxy group each having 1 to 10 carbon atoms and may have one or more substituents. Specific examples thereof include methoxy, ethoxy, n-butoxy, t-butoxy, propoxy and isopropoxy.

Examples of substituents in the aforementioned groups include halogen atoms, cyano and nitro.

Examples of the alkyl group and substituted alkyl group represented by R ₁₄ are the same as described above for R ₁₂ and R ₁₃ . Examples of the cycloalkyl group represented by R ₁₄ are cycloalkyl groups having 4 to 20 carbon atoms such as cyclopentyl, cyclohexyl, adamantyl, norbornyl, tricyclodecanyl, tetracyclododecanyl, and tricyclopentyl It includes. Examples of substituents for these cycloalkyl groups include hydroxy, halogen atoms, carboxy and alkyl or alkoxy groups having 1 to 4 carbon atoms.

Examples of the ring formed by R ₁₂ and R ₁₃ linked to each other include a ring in which R ₁₂ and R ₁₃ connected are one of the following groups.

-C (= O) -O-C (= O)-

-C (= O) -NH-C (= O)-

-CH ₂ -C (= O) -OC (= O)-

When -COOR ₁₄ represents a group which is decomposed by the action of an acid, examples of R ₁₄ include hydrocarbon groups having 2 to 20 carbon atoms (eg t-butyl, norbornyl and cyclodecanyl), tetrahydro Alkoxyethyl groups such as furanyl, tetrahydropyranyl, ethoxyethyl and isopropylethyl, lactone groups and cyclohexyloxyethyl.

Examples of divalent organic groups having 2 to 20 carbon atoms represented by X ₁ include 4 to 20 carbon sources such as alkylene groups having 2 to 20 carbon atoms such as ethylene and propylene, cyclobutylene and cyclohexylene Arylene groups having 6 to 20 carbon atoms such as cycloalkylene groups having a group, phenylene and the like, and divalent cycloolefin groups having a crosslink.

The substructure represented by the general formula (Id) may be included in the main chain or the side chain thereof. However, in the present invention, the partial structure is preferably contained in the main chain of the polymer.

Examples of the polymer having a repeating unit including the partial structure represented by the formula (I) include polymers represented by the following formulas (a-1d) to (a-10d).

In the polymer example, R represents methyl or ethyl. However, in the polymer containing the mixture of the substructure represented by the formula (Id), R represents methyl, and in the substructure represented by the formula (Id), R is ethyl and is also included in the present invention.

In an example of a process for polymerizing polymer (B), the phenolic compound and polybutadiene synthesize a polymer having a structural unit represented by the following general formula (IId) by using an alkylation reaction in the presence of a sanacatalyst. The obtained polymer is hydrogenated to obtain a polymer represented by the following general formula (IIId).

The polymer represented by the formula (IIId) is esterified with the carboxylic anhydride represented by the formula (IVd) to obtain the polymer represented by the formula (Vd).

The polymer represented by the formula (Vd) is further esterified with the supplied unit as necessary to obtain a polymer having a repeating unit represented by any one of (a-1d) to (a-10d).

(In the above formula, R ₁₁ to R ₁₃ have the same meaning as in formula (Id), and Z represents a divalent organic group.)

The said synthesis process is demonstrated in detail. First, the polymer represented by the formula (IId) is synthesized by the methods described in Japanese Patent Application Laid-Open No. 7-41536 and Japanese Patent Application Laid-open No. Hei 9-263672, and the phenolic compound and polybutadiene are subjected to an alkylation reaction in the presence of an acid catalyst to give a target polymer. Get

Examples of acid catalysts include boron trifluoride compounds such as boron trifluoride, boron trifluoride / ether mixtures and boron trifluoride / phenol compounds, fluoroalkylsulfonic acids, fluoroalkylcarboxylic acids, arylsulfonic acids, aluminum phenoxy Seeds, sulfonic acid, p-toluenesulfonic acid, methanesulfonic acid, boron fluoride, boron fluoride / ether mixtures, boron fluoride / phenol mixtures, aluminum chloride and perchloric acid. Preferred from the standpoint of catalytic activity and catalyst removal are boron trifluoride / ether mixtures and boron trifluoride / phenol mixtures. Especially preferred are boron trifluoride / phenol mixtures. Although the amount of acid catalyst to be used is not particularly limited, it is generally 5 to 50 mmol, preferably 10 to 20 mmol, per 100 g of polybutadiene. In the reaction of polybutadiene and phenolic compound, addition reaction of phenolic compound to polybutadiene occurs. Moreover, in this reaction, the polymer further performs intramolecular cyclization. Thus, the reaction system generates a very large amount of thermal reaction. As a result, the most preferred method for controlling the reaction temperature is to add polybutadiene to the system comprising gradually adding phenolic compounds and acid catalysts. Since the phenolic compound which did not react in this reaction is provided as a working solvent, it is not necessary to add a reaction solvent specially. However, a small amount of inert solvent can be used in a molar amount that will lower the viscosity of the reaction system. Examples of inert solvents include hydrocarbons such as toluene and xylene and halogenated solvents such as chlorobenzene and dichloroethane. The temperature for the reaction of the polybutadiene having a phenol compound is not particularly limited, and is preferably about 25 to 220 ° C.

Examples of the phenolic compound include phenol, o-cresol, m-cresol, p-cresol, t-butylphenol, cyclohexylphenol, p-cumylphenol, xylenes and naphthols. In the reaction between the polybutadiene and the phenolic compound, the amount occupied by the phenolic compound is generally 1.2 to 20 equivalents, preferably 2.5 to 12 equivalents, based on the total double bond of the polybutadiene.

A known method can be used to hydrogenate the polymer represented by the formula (IId) to obtain the polymer represented by the formula (IIId). For example, the polymer represented by formula (IId) is dissolved in a solvent and the solution is extracted in contact with hydrogen in the presence of a metal catalyst. It is preferable that the solvent generally dissolve the polymer represented by the formula (IId), be stable to hydrogenation, and be easily removable after hydrogenation. Preferable examples thereof include low alcohols such as methanol, ethanol, propanol and butanol, low ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, and cyclic ethers such as tetrahydrofuran and dioxane. Further preferred are phenols such as cresols. Particularly preferred among these solvents is low alcohols.

Preferred examples of metal catalysts include nickel, cobalt, palladium, platinum and rhodium. The catalyst metal may be used after being fixed or fixed to the metal oxide support. Generally, nickel and cobalt are used either alone or after being fixed to a porous support such as silica, alumina, carbon or diatomaceous earth. Precious metals are generally used in the form of oxides or after they are fixed to a support.

Although the amount of the catalyst used varies depending on the type of catalyst, its suitable range is generally as follows. Hydrogenation may be completed as an intermittent treatment such as autoclaving or as a continuous treatment by passing the reaction mixture through a fixed bed. In the case of intermittent treatment, a suitable range of catalyst amounts is about 0.1 to 10 kg / kg.hr of WHSV of the polymer based on the catalyst. In the case of a continuous flow process, a catalyst fixed to the support is generally used.

The temperature for hydrogenation is generally 10 to 200 kg / cm 2, preferably 50 to 100 kg / cm 2 from the viewpoint of reaction temperature, resistance pressure of the apparatus, and the like. The desired temperature range can be chosen depending on, for example, the type and amount of catalyst used and the condition for the treatment temperature, the nature of the polymer treated and the like. In the present invention, the hydrogenation degree of the aromatic nucleus is preferably at least 60%, more preferably at least 70%, most preferably at least 80%. Nuclear hydrogenation of less than 60% is undesirable because it results in increased light absorption at 193 nm and impairs the resist profile.

The method for obtaining the polymer represented by the formula (Vd) is described next. The polymer represented by the formula (Vd) is obtained by esterifying the polymer represented by the formula (IIId) with the carboxylic anhydride represented by the formula (IVd).

Examples of carboxylic anhydrides used for esterification are the same as those listed above.

The esterification reaction is described, for example, in R. P. Hanzilik, Org. Synth., VI, 560 (1988) or J. Cason, Org. By the method described in Synth., III, 169 (1955), the target polymer can be easily obtained. Specifically, the polymer represented by the formula (IVd) is dissolved in a solvent together with the carboxylic anhydride represented by the formula (Vd), and the reaction products are reacted with each other in the presence of a catalyst at a temperature of 5 to 150 ° C. to obtain a target polymer. Examples of solvents used herein include benzene, toluene, xylene, DMF and THF. The catalyst may be, for example, a base catalyst of pyridine, sodium acetate, 4-dimethylaminopyridine and triethylamine.

In the esterification reaction, the polymer represented by formula (IIId) and the carboxylic anhydride represented by formula (IVd) are 0.5 to 2.0 per 1.0 mole of polymer represented by formula (IIId). The occupied amount of carboxylic acid anhydride of 0.5 or less per polymer is not preferable because the polymer obtained as a result of the formula (Vd) has insufficient alkali solubility. On the other hand, when the amount occupied by the carboxylic acid anhydride exceeds 2.0 mol per polymer, the acid anhydride forms diester through alcohol decomposition. As a result, the polymer represented by the formula (Vd) has insufficient alkali solubility and provides a resist having reduced sensitivity. Therefore, it is desirable to control the reaction so that the acid anhydride forms half esters through alcoholic decomposition.

The positive photoresist composition included in the present invention may include a polymer represented by the formula (Vd) (polymer (B) without acid-decomposable group), an acid-decomposable dissolving inhibitor and a photoacid generator. However, preference is given to combining the acid-decomposable group with the polymer represented by the formula (Vd). That is, the partial structure represented by general formula (Id) preferably has an acid-decomposable group.

The acid-decomposable group is bonded with the polymer represented by the formula (Vd) by protecting the carboxyl group of the polymer through esterification. Examples of this esterification reaction include a method in which the polymer represented by the formula (Vd) esterifies tertiary alcohol with 4-dimethylaminopyridine (DMAP) or the like (G. Hoefle, W. Steglich, and Vorbrueggen, Angew. Chem. Int Ed. Engle., 17, 569 (1978)), methods using trifluoroacetic anhydride (RC PARISH and LMStock, J. Org. Chem., 30, 927 (1965)), and DCC (dicyclo Hexylcarbodiim) (B. Neises and W. Steglich, Org. Synth., 63, 183 (1985)).

In each of the above-described polymers (B) for use in the present invention, the content of the repeating unit having a partial structure represented by the formula (Ia), (Ib), (Ic) or (Id) is preferably based on the total repeating unit. 50 mol% or more, More preferably, it is 60 mol% or more.

In the case of the polymer (B) for use in the present invention, the content of the repeating structural unit each having an acid-decomposable group in each polymer is preferably 20 mol% or more, more preferably 30 mol% or more, based on the total repeating units, Most preferably 30 to 60 mole%.

In addition to the repeating unit having a partial structure represented by the formula (Ia), (Ib), (Ic) or (Id), another repeating unit may be included in each polymer (B) for the present invention.

The polymer average molecular weight of each polymer (B) is preferably in the range of 1,500 to 100,000, more preferably 2,000 to 70,000, most preferably 3,000 to 50,000. The molecular weight of 1,500 or less is not preferable because the dry etching resistance, heat resistance, and adhesion to the substrate are insufficient. If its molecular weight exceeds 100,000, the resist sensitivity decreases, which is not preferable.

The weight average molecular weight and molecular weight distribution (M _w / M _n ) of each polymer (B) is 1.0 to 6.0, more preferably 1.0 to 4.0. The smaller the molecular weight distribution, the better the heat resistance and burnability (resist profile, defocus latitude).

The weight average molecular weight and the molecular weight distribution (M _w / M _n ) of each polymer (B) are determined as standard polystyrene by gel permeation chromatography by applying a refractive index meter.

In each of the positive photosensitive resin compositions of the present invention, the content of the polymer (B) is generally 50 to 99.7% by weight, preferably 70 to 99% by weight based on the solid.

In addition to the polymer (B), one or more other polymers may be included in each positive photosensitive resin composition of the present invention. The content of another polymer is preferably up to 30 parts by weight, more preferably up to 20 parts by weight, most preferably up to 10 parts by weight per 100 parts by weight of the polymer (B).

Any polymer that can be included in each positive photosensitive resin composition of the present invention may be any polymer that is compatible with the polymer (B). Examples thereof include poly (p-hydroxyethylene), hydrogenated poly (p-hydroxyethylene), novolak resins and alicyclic polymers described in Japanese Patent No. 10-112219.

(Component (A))

A compound (A) (hereinafter referred to as a photoacid generator (A)) which is decomposed by irradiation of actinic rays and generates an acid contained in each positive photosensitive resin composition of the present invention will be described next.

Examples of photoacid generators (A) for use in the present invention include photoinitiators for cationic photopolymerization, photoinitiators for radical photopolymerization, photobleaching agents including colorants, photochromic agents, and microphotoresists And compounds known as photoacid generators that generate acids by irradiating ultraviolet rays, far ultraviolet rays, KrF excimer laser light, ArF escimer laser light, electron beams, X-rays, molecular molecules, ion beams, and the like. These photoacid generators may be used alone or as a mixture of two or more thereof.

In the present invention, "actinic radiation" is used in the sense of exorbitant of radiation including the above.

The photoacid generator (A) is not particularly limited as long as it is dissolved in an organic solvent that can be used in each of the positive photosensitive resin compositions of the present invention described later. However, a photoacid generator which generates an acid by irradiation of light having a wavelength of 220 nm or less is preferable. A single photoacid generator or a combination of two or more photoacid generators may be used. In addition, a suitable photosensitizer and one or more photoacid generators may be used in combination.

Examples of photoacid generators (A) that can be used are, for example, J. Org. Chem., Vol. 43, No. 15, 3055 (1978) and another kind of oil described in Japanese Patent No. 9-279071. Nium salts (ie, sulfonium salts, iodonium salts, phosphonium salts, diazonium salts, and ammonium salts).

Specific examples of onium salts include diphenyl iodonium triflate, diphenyl iodonium pyrenesulfonate, diphenyl iodonium dodecyl benzenesulfonate, tripenzyl sulfonium triflate, triphenylsulfonium hexafluoroantimonate and diphenyl Iodonium hexafluoroantimonate, triphenylsulfonium naphthalenesulfonate, triphenylsulfonium camphorsulfonium, (4-methoxyphenyl) phenyl iodoniumtrifluoromethanesulfonate.

Further preferred examples of the photoacid generator include diazo disulfones and diazoketo sulfones described in Japanese Patent Laid-Open No. 3-103854, Japanese Patent Laid-Open No. 3-103856 and Japanese Patent Laid-Open No. 4-1210960, Japanese Patent Laid-Open No. 64- Iminosulfonates described in 18143 and Japanese Patent Laid-Open No. 2-245756, and disulfones described in Japanese Patent Laid-Open No. 2-71270. Moreover, the polymeric compound which has a thing couple | bonded with the main chain or its side chain, for example, US Patent No. 3,849,137, Japanese Patent Laid-Open No. 63-26653, Japanese Patent Laid-Open No. 62-69263, Japanese Patent Laid-Open 63-146038, Japan Compounds which generate an acid by irradiation with light described in Japanese Patent Application Laid-Open No. 63-163452, Japanese Patent Laid-Open No. 62-153853 and Japanese Patent Application Laid-Open No. 63-146029 are useful. Further preferred examples of the photoacid generator include 2-oxocyclohexyl groups described in Japanese Patent Laid-Open No. 7-25846, Japanese Patent Laid-Open No. 7-28237, Japanese Patent Laid-Open No. 7-92675, and Japanese Patent Laid-Open No. 8-27120. Aliphatic alkylsulfonium salts, N-hydroxysuccinimidesulfonates and J. Photopolym. Sci., Tech., Vol. 7. No. 3, sulfonium salts described in 423 (1944). These photoacid generators may be used alone or in combination of two or more thereof.

The content of these compounds (A) which are decomposed by irradiation of actinic rays to generate an acid is generally 0.001 to 40% by weight, preferably 0.01 to 20% by weight, more preferably based on the total amount (solid basis) of the photosensitive resin composition. 0.1 to 5% by weight. The content of the photoacid generator (A) of 0.001% by weight or less is not preferable because the sensitivity is reduced. Its content of at least 40% by weight is undesirable because the resist shows too high light absorption, resulting in profile damage and narrow process margins, especially narrow bake margins.

(Component (C))

The nitrogen containing basic compound (C) contained in each positive photosensitive resin composition of this invention is demonstrated next. The nitrogen-containing basic compound is not particularly limited as long as it does not impair sublimation or resistivity. Examples thereof include organic amines, base ammonium salts, and sulfonium salts.

For example, the use is, for example, Japanese Patent Laid-Open No. 63-149640, Japanese Patent Laid-Open No. 5-249662, Japanese Patent Laid-Open No. 5-127369, Japanese Patent Laid-Open No. 5-289322, Japanese Patent Laid-Open No. 5-249683, Japanese Patent Laid-Open Publication No. 5-289340, Japanese Patent Laid-Open Publication 5-232706, Japanese Patent Laid-Open Publication 5-257282, Japanese Patent Laid-Open Publication 6-242605, Japanese Patent Laid-Open Publication 6-242606, Japanese Patent Laid-Open Publication 6-266100 Japanese Patent Laid-Open No. 6-266110, Japanese Patent Laid-Open 6-317902, Japanese Patent Laid-Open No. 7-120929, Japanese Patent Laid-Open No. 7-146558, Japanese Patent Laid-Open No. 7-319163, Japanese Patent Laid-Open No. 7-508840, Japanese Patent Laid-Open No. 7 -333844, JP 7-219217, JP 7-92678, JP 7-28247, JP 8-22120, JP 8-110638, JP 8-123030 Japanese Patent Laid-Open No. 9-274312, Japanese Patent Laid-Open No. 9-166871, Japanese Patent Laid-Open No. 9-292708, Japanese Patent Laid-Open No. 9-325496, Japanese Patent Laid-Open No. 7-508840, US Patent No. 5,525453 And basic compounds described in US Pat. Nos. 5,629,134 and 5,667,938. The.

Particularly preferred examples of the basic compound (C) are 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5.4.0] -7-undecene, 1,4-dia Xavicyclo [2.2.2] octane, 4-dimethylaminopyridine, 1-naphthylamine, piperidine, hexamethylenetetraamine, imidazole and analogues thereof, hydroxypyridines, pyridine analogs, 4,4 ' -Diaminodiphenylether, pyridinium, p-toluenesulfonate, 2,4,6-trimethylpyridinium p-toluenesulfonate, tetramethylammonium p-toluenesulfonate and tetrabutylammonium lactate.

The basic compound (C) may be used alone or in combination of two or more thereof.

The content of the nitrogen-containing basic compound (C) is 0.001 to 10 parts by weight, preferably 0.01 to 5 parts by weight, per 100 parts by weight (solid basis) of the photosensitive resin composition. If its content is 0.001 or less, sufficient effect cannot be obtained. If its content exceeds 10 parts by weight, this results in reduced sensitivity and relatively developability in the non-exposed areas.

(Component (D))

The fluorine type and / or silicon type surfactant (D) contained in each of the positive photosensitive resin compositions of the present invention will be described next.

Each photosensitive resin composition of the present invention may include a fluorine type surfactant, a silicone type surfactant, and a surfactant containing both a fluorine atom and a silicon atom, and may contain two or more of these surfactants.

Examples of surfactants (D) are U.S. Patent Nos. 5,405,720, 5,360,692, 5,529,881, 5,296,330, 5,436,098, 5,576,143, 5,294,511 and 5,824,451, Japanese Patent Laid-Open No. 62-36663, JP 61-226746, JP 61-226745, JP 62-170950, JP 63-34540, JP 7-230165, JP 8-62834, JP Surfactants described in Japanese Patent Laid-Open No. 9-54432 and Japanese Patent Laid-Open No. 9-5988. In addition, commercially available surfactants can be used as follows.

Examples of the surfactant that can be used as the product include F-TopEF301 and EF303 (manufactured by New Akita Chemical Co., Ltd.), Floro FC430 and FC431 (manufactured by Sumitomo 3M Co., Ltd.), MegaPac F171, F173, F176, F189, and R08. (Dinippon Ink & Chemical Co., Ltd.) and fluorine type and / or such as Supron S-382, SC-101, SC-102, SC-103, SC104, SC105, and SC106 (manufactured by Asahi Glass Co., Ltd.) Silicon type interfacial sulfur agent is included. Polysiloxane polymer KP-341 (made by Shin-Echu Chemical Co., Ltd.) can be used as a silicone type surfactant.

Particularly preferred of these surfactants, from the viewpoint of alleviating the development defect, contain both fluorine and silicon atoms, respectively.

The mixing amount of the surfactant (D) is generally 0.01 to 2 parts by weight, preferably 0.01 to 1 part by weight, per 100 parts by weight of the solid-based composition of the present invention. These surfactants can be used alone or in combination of two or more thereof.

(Another ingredient)

A low molecular weight, acid-decomposable dissolution inhibiting compound may be included in each of the positive photosensitive resin compositions of the present invention if necessary. This compound has a molecular weight of 2,000 or less, has one or more groups degradable by the action of an acid, and increases the solubility of alkali by the action of an acid.

Examples of low molecular acid degradable compounds are described, for example, in Proc. SPIE, 2724, 355 (1996), Japanese Patent Laid-Open Nos. 8-15865, U.S. Patents 5,310, 619 and 5,372,912 and J. Photopolym. Sci., Tech., Vol. 10, No. 3, 511 (1997). Examples include alicyclic compounds such as choline acid derivatives having at least one acid-decomposable group, dehydric choline derivatives, deoxycholine derivatives, lysocholine derivatives, urosocholine derivatives and abietin acid derivatives; And aromatic compounds such as naphthalene derivatives having at least one acid-decomposable group.

Furthermore, the low molecular weight, acid decomposability, and dissolution inhibiting compound described in Japanese Patent Laid-Open No. 6-51519 can be used in a small amount as long as the transmittance is not reduced at 220 nm. In addition, 1,2-naphthoquinonediazide compounds can be used.

In the case where the above-mentioned low molecular weight, acid decomposable, dissolution inhibiting compound is used in the photosensitive resin composition of the present invention, its content is generally 1 to 50% by weight, preferably 3 to 3, based on the total amount of the photosensitive resin composition (solid basis). 40 wt%, more preferably 5 to 30 wt%.

The addition of a low molecular weight, acid-decomposable dissolution inhibiting compound not only improves the effect of alleviating development defects, but also improves dry etching resistance.

Each positive photosensitive resin composition of the present invention is, for example, a developer, an antihalation agent, a plasticizer, a surfactant, a photosensitizer, an adhesion improving agent, a crosslinking agent and a compound for increasing solubility in a photo-base generator, and the like. Another component may further optionally be included.

Examples of the compound which increases the solubility in the developing solution which can be used in the present invention include, for example, compounds having two or more phenolic hydroxyl groups described in Japanese Patent Application Laid-Open No. 3-206458, compounds having one or more carboxyl groups, carboxylic anhydrides, And low molecular weight compounds having a molecular weight of 1,000 or less, such as sulfonamide compounds and sulfonylimide compounds.

The mixing amount of these solubility increasing compounds is preferably up to 30% by weight, more preferably up to 20% by weight, based on the total amount (solid basis) of the composition.

Preferred antihalation agents are compounds which sufficiently absorb the radiation to which the composition is irradiated. Examples thereof include substituted benzenes such as fluorene, 9-fluorenone, and benzophenone, and polycyclic aromatic compounds such as anthracene, anthracene-9-methanol, anthracene-9-carboxyethyl, phenanthrene, perylene, and acetylene. Include. These antihalation agents have the effect of improving the standing wave by eliminating light reflection by the substrate and reducing the influence of multiple reflections in the resist film.

Examples of nonionic surfactants that can be used with the aforementioned essential ingredients include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene nonylphenyl ether, polyethylene glycol dilaurate, Polyethylene glycol distearate, polyoxyethylene sorbitan monostearate and sorbitan monolaurate.

Photosensitizers may be added to improve the efficiency of acid generation upon exposure. Preferred examples of photosensitizers are benzophenone, p, p'-tetramethyldiminobenzophenone, 2-chlorothioxanthone, anthrone, 9-ethoxyanthracene, pyrene, phenothiazine, benzyl, benzoflavin, Acetophenone, phenanthrene, benzoquinone, anthraquinone, and 1,2-naphthoquinone. However, the photosensitizer which can be used for this invention is not limited to these examples and is not comprised. These photosensitizers can be used as the antihalation described above.

In the solution formation of the present invention, each photosensitive resin composition is prepared by decomposing the components of the soluble solvent and filtering the resulting solution through a filter having a diameter of, for example, approximately 0.05 to 0.2 μm. Examples of the solvent are ethylene glycol monoethyl ether acetate, cyclohexanone, 2-heptanone, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether propionate, propylene glycol monoethyl ether acetate, methyl 3-methoxypropionate, ethyl3-ethoxypropionate, methylβ-methoxyisobutyrate, ethylbutyrate, propylbutyrate, methylisobutyl ketone, ethyl acetate, isoamyl acetate, ethyl lactate, toluene, xylene , Cyclohexyl acetate, diacetone alcohol, N-methylpyrrolidone, N, N-dimethylformamide, γ-butyrolactone, and N, N-dimethylacetamide. These solvents may be used alone or in combination of two or more thereof.

Solvent selection is important because it affects the solubility of each photosensitive resin composition of the present invention, the applicability to the substrate, the storage stability, and the like. Moreover, solvents having a low water content are preferred because the water contained therein affects these performances.

In the photosensitive resin composition of the present invention, the impurity content containing metal and chloride ions is preferably reduced to 100 ppb or less. The photosensitive resin composition containing a large amount of the above impurity is undesirable because the resulting semiconductor device has a malfunction or defect, or the use of the composition results in a reduced yield in semiconductor device production.

The photosensitive resin composition of the present invention is applied to the substrate, for example, by a suitable coating apparatus of a spinner or applicator, and the coating film is applied to a pre-baking (pre-exposure heating), so that it is 220 nm or less through a provided mask. It is exposed to exposure with a wavelength. The exposed film is applied to PEB (post exposure bake) and developed so that a satisfactory resist pattern can be obtained.

The substrate used herein is not particularly limited as long as it is a substrate generally used in semiconductors and other devices. Examples thereof include silicon substrates, glass substrates, and nonmagnetic ceramic substrates. These substrates have one or more additional layers arbitrarily formed over a silicon oxide layer, a metal layer for wiring, an interlayer insulating film, a magnetic film, an antireflective layer, and the like. The substrate may have various wirings, circuits, etc. previously formed here. Moreover, these substrates are made hydrophobic in a general manner to increase the adhesion of the resist film. Suitable hydrophobicizing agents include 1,1,1,3,3,3-hexamethyldisilazane (HMDS).

The thickness of the resist film formed on the substrate by coating is preferably in the range of 0.1 to 10 mu m. In the case of exposure with an ArF excimer laser, a thickness of about 0.1 to 1.5 mu m is recommended.

The resist film to be formed on the substrate is preferably prebaked at a temperature of 60 to 160 ° C. for about 30 to 300 seconds. Too low temperatures and too short periods for prebaking are undesirable because the prebaked resist film has a relatively large amount of residual solvent, which leads to poor results, for example, reducing adhesion. Too high temperatures and too long periods for prebaking are undesirable because the constituents of the photosensitive resin composition, such as, for example, binders and photoacid generators, decompose or otherwise have undesirable consequences. The prebaked resist film may use, for example, a commercially available light emitter such as an ultraviolet light emitter, an X-ray light emitter, an electron beam emitter, a KrF excimer emitter, an ArF excimer emitter, or an F ₂ excimer emitter. In the present invention, it is particularly preferable to use a light emitter to which an ArF excimer laser is applied as the exposure source.

The post-exposure bake is carried out for the purpose of causing acid-catalyzed removal of the protecting group, removing standing waves, and diffusing the acid generator or the like into a film or the like. The post-exposure bake may be performed in the same manner as the prebaking described above. For example, the baking temperature is generally 60 ° C to 160 ° C, preferably 90 to 150 ° C.

As a developing solution for the photosensitive resin composition of the present invention, use may be, for example, primary alkalis such as inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate or aqueous ammonia, ethylamine or n-propylamine, di Secondary amines such as ethylamine or di-n-butylamine, tertiary amines such as triethylamine or methyldiethylamine, alcohol amines such as dimethylethanolamine or triethanolamine, tetramethylammonium hydroxide (TMAH), tetra hydroxide Quaternary ammonium salts such as ethylammonium (TEAH), trimethylhydroxymethylammonium hydroxide, triethylhydroxyethylammonium hydroxide or trimethylhydroxyethylammonium hydroxide or pyrrole, piperidine, 1,8-diazabicyclo [5.4.0 ] -7-undecene or 1,5-diazabicyclo [4.3.0] -5-nonane and the like.

The alkaline aqueous solution may contain an appropriate amount of additives including, for example, hydrophobic organic solvents such as alcohols and ketones, nonionic or anionic surfactants, cationic surfactants, and foaming agents. In addition to being used to improve resistability, these additives are, for example, for the purpose of increasing adhesion to the substrate, reducing the amount of developer used, and removing defects that may occur with bubbles present during development. It can be added to an alkaline aqueous solution.

The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to this.

Synthesis Example 1

Synthesis of Polymer a-1

282 g (3 moles) of phenol and 8.2 g of ethanesulfonic acid were charged as a catalyst into a glass reaction vessel equipped with a thermometer and a stirrer. The ingredients were heated with stirring to 90 ° C. 132.2 g (1 mol) of dicyclopentadiene was added dropwise thereto for 4 hours. After completion of the addition, the components were heated at 150 ° C. and reacted at this temperature for 5 hours. After completion of the reaction, the resulting viscous reaction mixture was heated at 160 ° C. under vacuum to prevent unreacted phenol and other volatile substrates. Was regenerated. For distillation, 500 g of toluene was added to provide a homogeneous solution. Subsequently, this solution was separated into two layers. The water-soluble layer was applied as the lower layer, and toluene was removed from toluene as the upper layer by vacuum distillation to give 268 g of polymer A '. Its weight average molecular weight was measured by GPC and found to be 4,560. This polymer had a softening point of 128 ° C.

A solution prepared by 100 g of polymer A 'and a nickel catalyst in 200 g of butanol held in diatomaceous earth was placed in an autoclave having a capacity of 1 L. The atmosphere in the autoclave was replaced with nitrogen for several hours and hydrogen for several hours. Then, the hydrogen pressure in the autoclave was measured at 50 kg / cm 2, the content was heated with stirring, and set at 200 ° C. for 8 hours. After cooling. The resulting reaction mixture was filtered to remove the catalyst. The filtrate was added dropwise to 100 folds by weight of water to precipitate the polymer. The precipitated polymer was collected and dried in vacuo at 50 ° C. to obtain 90 g of polymer A ″. This polymer A ″ had a weight average molecular weight of 4,790. The hydrogenation degree of the phenol nucleus was calculated by IR and NMR spectrometer system and found to be 95%.

Subsequently, 47 g of Polymer A "and 38 g of 1,2-cyclohexanedicarboxylic acid anhydride were placed in a three-necked flask. 300 ml of THF was added thereto to dissolve these components. In this solution, 19 g of hydroxide Sodium was gradually added dropwise and the mixture was allowed to react for 6 hours at 40 ° C. The reaction mixture resulting from the reaction was poured into water to form crystals.After removing the remaining reaction product without reaction, the catalyst was extracted by filtration, Vacuum drying at 50 ° C. yielded 56 g of polymer A ″. This polymer A "had a weight average molecular weight of 6,200.

Furthermore, 20 g of polymer A "'and 21 mL of thionyl chloride mixture were refluxed for 1 hour. The excess solid was removed to dissolve the remaining solid in 90 mL of THF. The reaction mixture was allowed to react for 6 hours. The resulting solid was collected by filtration, washed with water and dried under vacuum The purified reaction product was recrystallized from n-hexane to give the polymer according to the invention (a-). This polymer (a-1) had a dispersion degree of weight average molecular weight 6,570 and 3.1.

Synthesis Example 2

(Synthesis of Polymer (a-1))

Synthesis Example 1 except that 3,6-endomethylene-4,5-dihydro-1,2,3,6-tetrahydrophthalic anhydride is used instead of 1,2-cyclohexanedicarboxylic acid anhydride The same process was carried out. Thus, the polymer (a-1) according to the present invention was obtained. This polymer (a-3) had a weight average molecular weight of 6,890 and a degree of dispersion of 3.1.

Synthesis Example 3

Synthesis of Polymer (a-11)

In 80 g of THF, 20 g of polymer A '' 'obtained in Synthesis Example 1 was dissolved. The dissolved polymer was reacted with 4.9 g of 3,4-dihydro-2H-pyran. The reaction product was coagulated with hexane, According to (a-11), which had a weight average molecular weight of 6,770 and a degree of dispersion of 3.1.

Synthesis Example 4

Synthesis of Polymer (a-23)

The same process as in Synthesis Example 1 was carried out except that α-naphthol was used instead of the phenol used as the starting material. Thus, a polymer (a-23) according to the present invention was obtained. This polymer (a-23) had a weight average molecular weight of 4,390 and a dispersion degree of 2.7.

Synthesis Example 5

(Synthesis of Acid Degradable Low Molecular Weight Compound a)

A mixture of 122.7 g (0.3 mol) of choline acid and 120 mL of thionyl chloride was refluxed for 1 hour. Excess thionyl chloride was removed and the residual solid was dissolved in 150 ml tetrahydrofuran. 40 g (0.35 mole) of potassium t-butoxide was gradually added to the solution. The reaction mixture was refluxed for 6 hours, then cooled and poured into water. The obtained solid was collected by filtration and dried in vacuo. This crude reaction product was recrystallized from n-hexane to give 70% yield of t-butylcholate (shown below).

Synthesis Example 6

(Synthesis of Polymer (b-1): Comparative Example)

A copolymer of 1-cyclohexyl-3-carboxylic acid and t-butyl methacrylate was obtained according to the method of Synthesis Example 1 described in JP-A-9-325498.

Synthesis Example 7

(Synthesis of Polymer (b-2): Comparative Example)

A copolymer of norbornenedicarboxylic acid, t-butyl methacrylate and methyl acrylate was obtained according to the method of Synthesis Example 6 described in JP-A-9-325498.

(Examples 1 to 4 and Comparative Examples 1 to 4)

(Production of Photosensitive Resin Composition)

The photosensitive resin composition was prepared from the components shown in Table 1. That is, the components used were polymers selected from polymers (a-1), (a-3), (a-11) and (a-23) synthesized in Synthesis Examples 1 to 4 and synthesized in Synthesis Examples 6 and 7. Polymer (b-2); Triphenylsulfonium triflate (PAG-1) as a photoacid generator; Acid-decomposable low molecular weight compounds synthesized in Synthesis Example 5; Nitrogen-containing base compounds; Surfactants and solvents were used. In Table 1, each dotted line indicates that the component is omitted.

The components were mixed together and the mixture was filtered through a 0.1 μm Teflon filter to prepare a photosensitive resin composition.

When using the ingredients, they were mixed in the following amounts.

9.0g polymer

Photoacid Generator 0.10g

Acid Degradable Low Molecular Weight Compound 1.0g

0.01 g of nitrogen-containing basic compounds

0.003 g of surfactant

Solvent 55.12 g

polymer Photoacid generator Acid-degradable low molecular weight compound Nitrogenous Base Compound Surfactants menstruum Example 1 (a-1) PAG-1 --- N-1 W-1 S-2 Example 2 (a-3) PAG-1 --- N-2 W-1 S-1 Example 3 (a-11) PAG-1 Compound a N-3 W-2 S-2 Example 4 (a-23) PAG-1 Compound a N-1 W-2 S-1 Comparative Example 1 (a-1) PAG-1 --- --- --- S-1 Comparative Example 2 (a-3) PAG-1 --- --- W-1 S-1 Comparative Example 3 (b-1) PAG-1 --- N-1 W-1 S-1 Comparative Example 4 (b-2) PAG-1 Compound a N-3 W-2 S-2

Formation for Positive Photoresist Composition

PAG-1: triphenylsulfonium triflate

N-1: 1,5-diazabicyclo [4.3.0] -5-nonene

N-2: 1,8-diazabicyclo [5.4.0] -7-undecene

N-3: 1,4-diazabicyclo [2.2.2] octane

W-1: Megapak F176 (fluorine type surfactant made by Dainippon Ink & Chemical Co., Ltd.)

W-2: Megapak R08 (fluorine and silicone type surfactant made by Dainippon Ink & Chemical Co., Ltd.)

S-1: Propylene Glycol Monomethyl Ether Acetate

S-2: ethyl lactate

The photosensitive resin composition thus prepared was evaluated for the development defect, the imageability of the resist and the dry etching resistance by the following method. The evaluation results for the development defects, the evaluation on the burnability and the evaluation on the dry etching resistance are shown in Table 1, Table 1, and Table 3, respectively.

(Evaluation method of image defect)

(1) Applying each photosensitive resin composition to a silicon substrate treated with hexamethyldisilazane with a spin coater, the coating was dried on a hot plate at 140 ° C. for 90 seconds to have a thickness of 0.50 μm. A resist film was formed. The resist film was exposed to an ArF excimer laser through a mask and immediately heated on a hotplate at 140 ° C. for 90 seconds. The resist film was then developed with a 2.38% aqueous solution of tetramethylammonium hydroxide at 23 ° C. for 60 seconds, rinsed with pure water for 30 seconds and dried. The sample thus obtained was tested with KLA2112 manufactured by KLA Tencol Co., Ltd., and the development defect function was counted (threshold, 12: pixel size, 0.39).

(2) Image defect function II

A sample was obtained in the same manner as in the image defect function I, except that the resist film was heated, developed, rinsed, and dried without exposure. This sample was tested in the same way to count the development defects.

(Method of image evaluation)

A 0.50 mu m resist film was formed in the same manner as in the development defect I. This film was exposed, heated, developed, rinsed, and dried in the same manner. Therefore, the film thickness was measured with a film thickness meter to determine the enteric film ratio.

Moreover, the profile of the line pattern thus obtained having a line of 0.20 mu m was tested by scanning electron microscopy. A pattern having a rectangular flow pile is represented by A, and a non-rectangular profile is represented by B. FIG. The resolution is shown as the limit resolution at the exposure dose necessary for reproducing the 0.30 mu m mask pattern.

(Dry etching resistance determination)

Each photosensitive resin composition shown in Table 1 was filtered through a Teflon filter having an opening diameter of 0.1 μm. The composition was applied flat on the silicon substrate with a spin coater and dried on a hotplate at 130 ° C. for 90 seconds to form a resist film having a thickness of 0.70 μm. The obtained film was etched by CF ₄ / O ₂ (8/2) by an apparatus of an inert etching device (CSE-1110) manufactured by ULVAC. The obtained results are shown in Table 4.

Developing Defect I Development Defects II Example 1 2 3 Example 2 2 4 Example 3 One One Example 4 2 2 Comparative Example 1 23 35 Comparative Example 2 15 16 Comparative Example 3 5 6 Comparative Example 4 3 4

Phenomenon

Residual Film Ratio (%) profile Limit resolution (㎛) Example 1 99.8 A 0.15 Example 2 99.8 A 0.15 Example 3 99.9 A 0.13 Example 4 99.9 A 0.13 Comparative Example 1 99.7 A 0.15 Comparative Example 2 99.4 A 0.15 Comparative Example 3 98.0 B 0.28 Comparative Example 4 97.2 B 0.23

Resistivity of resist

Etch Rate (m / min) Example 1 700 Example 2 720 Example 3 770 Example 4 730 Comparative Example 1 705 Comparative Example 2 715 Comparative Example 3 980 Comparative Example 4 930

Dry etching resistance of the resist; Dry etching rate

As can be seen from the results shown in Table 2, the photosensitive resin composition according to the present invention each provided a resist film almost free of development defects. In contrast, the compositions obtained in Comparative Examples 1 and 2 which do not contain at least one of the nitrogen-containing base compound (C) and the surfactant (D) are inferior in developability.

As can be seen from the results given in Table 3, the photosensitive resin composition according to the present invention was remarkably excellent in the residual film ratio, resolution and profile, respectively. In contrast, the compositions obtained in Comparative Examples 3 and 4 fall in resolution and profile.

As can be seen from the results given in Table 4, the photosensitive resin composition according to the present invention provides a resist film each having excellent dry etching resistance. In contrast, the resist films obtained in the compositions of Comparative Examples 3 and 4 had insufficient dry etching resistance.

The invention will be explained in more detail with reference to the following examples using polymers having a partial structure represented by formula (1b). However, the present invention is not limited to these examples.

Synthesis Example 1b

Synthesis of Polymer (a-1b)

In a working flask having a capacity of 500 µl, 188 g of phenol was added. The phenol was dissolved by heating at 80 ° C. 1.42 g of ethyl ether boron trifluoride was added thereto. While stirring the mixture, 66 g of dicyclopentadiene was added dropwise for 3 hours. Thereafter, 61.7 g 35% water-soluble formaldehyde solution was added dropwise at 100 ° C. for 2 hours, and the resulting mixture was further reacted for 1 hour to obtain a reaction mixture containing a modified phenolic resin. The phenol remaining unreacted was distilled under vacuum at 100 to 180 ° C. to remove it from the reaction mixture, and 550 g of toluene was added to the residue to dissolve. 900 g of ion-exchanged water was added to the solution. After this washing operation was performed five times or more, toluene and other volatile substrates were removed from the toluene solution by vacuum distillation at 100 to 180 占 폚. The residue was cooled to give about 200 g of modified phenolic resin (polymer Ab ').

The solution prepared by dissolving 100 g of polymer Ab 'and 3 g of nickel catalyst supported by diatomaceous earth in 200 g of ethanol was placed in a 1 L autoclave. The atmosphere of the autoclave was placed several times with nitrogen and several times with hydrogen. Thereafter, the hydrogen pressure in the autoclave was adjusted to 50 kg / cm < 2 >, and the components were heated with stirring to leave at 200 ° C for 8 hours. After cooling, the resulting reaction mixture was filtered to remove catalyst. The filtrate was dropped into 10 folds by weight of water to precipitate the polymer. The precipitated polymer was collected and dried in vacuo at 50 ° C. to obtain 90 g of Polymer Ab ”. This polymer Ab” had a weight average molecular weight of 4,960. The hydrogenation degree of the phenol nucleus was found to be 92% calculated by IR and NMR spectrophotometer.

Subsequently, 56 g of polymer Ab "and 38 g of 1,2-cyclohexanedicarboxylic anhydride were placed in a three-necked flask. 300 ml of THF was added thereto to dissolve these components. 19 g of pyridine was added to the solution. The mixture was added dropwise gradually and the mixture was reacted for 6 hours at 40 ° C. The resulting reaction mixture was poured into water and recrystallized After removing the remaining reaction product without reaction, the catalyst was extracted by filtration and at 50 ° C. By vacuum, 56g of polymer Ab "'was obtained. This polymer Ab "'had a weight average molecular weight of 6,780.

Furthermore, a mixture of 20 g of polymer Ab " 'and 21 mL of thionyl chloride was refluxed for 1 hour. The excess solid was removed to dissolve the remaining solid in 90 mL of THF. The solution was dissolved in 8 g of potassium t Gradually added to butoxide, the reaction mixture was horned for 6 hours, cooled continuously and poured into water The solid obtained was collected by filtration, rinsed with water and dried in vacuo The purified reaction product was n-hexane Recrystallization from gave polymer (a-1) according to the present invention, polymer (a-1) had a weight average molecular weight of 6,920 and a degree of dispersion of 3.0.

Synthesis Example 2b

Synthesis of Polymer (a-2b)

Synthesis Example 1b and 3 except that 3,6-endomethylene-4,5-dihydro-1,2,3,6-tetrahydrophthalic anhydride was used in place of 1,2-cyclohexanedicarboxylic acid anhydride It carried out by the same process. Thus, a polymer (a-3b) according to the present invention was obtained. This polymer (a-3b) had a weight average molecular weight of 6,890 and a dispersion degree of 3.0.

Synthesis Example 3b

(Synthesis of Polymer a-6b)

20 g of the polymer Ab " 'obtained in Synthesis Example 1b was dissolved in 80 g of THF. The dissolved polymer was reacted with 4.9 g of 3,4-dihydro-2H-pyran. The reaction product was coagulated with hexane, (A-6b), which had a weight average molecular weight of 6,700 and a degree of dispersion of 3.0.

Synthesis Example 4b

Synthesis of Polymer (a-12b)

The same process as in Synthesis Example 1b was carried out except that α-naphthol was used instead of the phenol used as the starting material. Thus, a polymer (a-12b) according to the present invention was obtained. This polymer (a-12b) had a weight average molecular weight of 4,230 and a dispersion degree of 2.6.

(Examples 1b to 4b and Comparative Examples 1b to 4b)

(Production of Photosensitive Resin Composition)

The photosensitive resin composition was prepared from the components shown in Table 5. That is, the components used were polymers (a-1b), (a-2b), (a-6b) and (a-12b) synthesized in Synthesis Examples 1b to 4b and polymers synthesized in Synthesis Examples 6 and 7 (b). -1) and a polymer selected from (b-2); Triphenylsulfonium triflate (PAG-1) as a photoacid generator; Acid-decomposable low molecular weight compounds synthesized in Synthesis Example 5; Nitrogen-containing basic compounds; Surfactants; And solvents were used. In Table 5, each dashed line means that the component is omitted.

The components were mixed together and the mixture was filtered through a 0.1 μm Teflon filter to prepare a photosensitive resin composition.

When using the ingredients, they were mixed in the following amounts.

9.0g polymer

Photoacid Generator 0.10g

Acid Degradable Low Molecular Weight Compound 1.0g

0.01 g of nitrogen-containing basic compounds

0.003 g of surfactant

Solvent 55.12 g

polymer Photoacid generator Acid Degradable Low Molecular Compounds Nitrogenous Base Compound Surfactants menstruum Example 1b (a-1b) PAG-1 --- N-1 W-1 S-2 Example 2b (a-2b) PAG-1 --- N-2 W-1 S-1 Example 3b (a-6b) PAG-1 Compound a N-3 W-2 S-2 Example 4b (a-12b) PAG-1 Compound a N-1 W-2 S-1 Comparative Example 1b (a-1b) PAG-1 --- --- --- S-1 Comparative Example 2b (a-2b) PAG-1 --- --- W-1 S-1 Comparative Example 3b (b-1) PAG-1 --- N-1 W-1 S-1 Comparative Example 4b (b-2) PAG-1 Compound a N-3 W-2 S-2

The photosensitive resin composition thus prepared was evaluated for the development defect, the burnability and the dry etching property of the resist in the same manner as in the above-described examples. Evaluation results for development defects, evaluation results for burnability, and evaluation results for dry etching resistance are shown in Tables 6, 7, and 8, respectively.

Developing Defect I Development Defects II Example 1b One 2 Example 2b 2 3 Example 3b One One Example 4b One 2 Comparative Example 1b 22 31 Comparative Example 2b 13 12 Comparative Example 3b 5 6 Comparative Example 4b 3 4

Residual Film Ratio (%) profile Limit resolution (㎛) Example 1b 99.8 A 0.16 Example 2b 99.8 A 0.15 Example 3b 99.9 A 0.13 Example 4b 99.9 A 0.13 Comparative Example 1b 99.7 A 0.16 Comparative Example 2b 99.4 A 0.15 Comparative Example 3b 98.0 B 0.28 Comparative Example 4b 97.2 B 0.23

Etching Rate (m / min) Example 1b 720 Example 2b 730 Example 3b 700 Example 4b 710 Comparative Example 1b 720 Comparative Example 2b 730 Comparative Example 3b 980 Comparative Example 4b 930

As shown in Table 6, each of the photosensitive resin compositions according to the present invention provided a resist film almost free of development defects. On the contrary, the compositions included in Comparative Examples 1b and 2b which do not contain at least one of the nitrogen-containing basic compound (C) and the surfactant (D) have low development defects.

As shown in Table 7, the photosensitive resin composition according to the present invention is remarkably excellent in residual film ratio, resolution and profile, respectively. In contrast, the compositions obtained in Comparative Examples 3b and 4b fall in resolution and profile.

The present invention will be explained in more detail with reference to the following examples using a polymer having a partial structure represented by formula (Ic). However, the present invention is not limited to these examples.

Synthesis Example 1c

Synthesis of Polymer (a-1c)

800 g phenol and 150 g toluene were placed in a 2.5 L reaction vessel equipped with a reflux condenser and a Liebich cooler. The components were heated at 170 ° C. to distill 250 g of toluene. The system was dehydrogenated until the water content was 50 ppm. Subsequently, the system was cooled at 80 ° C., and 185 g of 5-norbornene having a water concentration of 20 ppm was gradually added dropwise for 1.5 hours. After the addition was complete, the reaction mixture was further reacted at 80 ° C. for 40 minutes, then heated at 140 ° C. and stirred at this temperature for 2.5 hours. Thus, 40 g of magnesium compound "KW-1000" (trade name: manufactured by Kyowa Chemical Co., Ltd.) was added and the reaction mixture was stirred for 60 minutes to inactivate the catalyst. The reaction mixture was filtered through a filter paper covered with celite. The clean filtrate thus obtained was distilled at 230 ° C. under reduced pressure to obtain 270 g of polymer Ac '.

A solution prepared by 100 g of polymer Ac 'in 200 g of t-butyl alcohol and 3.5 g of nickel catalyst supported on diatomaceous earth was placed in a 1 L autoclave. The atmosphere in the autoclave was replaced several times with nitrogen and several times with hydrogen. Then, the hydrogen pressure in the autoclave was adjusted to 50 kg / cm 2, and the components were heated with stirring to leave at 200 ° C. for 10 hours.

After cooling, the resulting reaction mixture was filtered to remove catalyst. The filtrate was dropped into 10 folds by weight of water to precipitate the polymer. The precipitated polymer was collected and dried in vacuo at 50 ° C. to give 82 g of polymer Ac ″. This polymer Ac ″ had a weight average molecular weight of 4,210. The hydrogenation of its phenol nucleus was found to be 94%, calculated through TR and NMR spectrophotometers.

Subsequently, 53 g of polymer Ac "and 39 g of 1,2-cyclohexanedicarboxylic anhydride were placed in a three-necked flask. 300 ml of THF was added thereto to dissolve these components. 20 g of sodium hydroxide was dissolved in this solution. Was added dropwise and the mixture was reacted for 6 hours at 40 ° C. The resulting reaction mixture was poured into water and crystallized After removing the remaining reaction product without reaction, crystals were extracted by filtration to give 53 g of Polymer Ac "'was obtained. This polymer Ac "'had a weight average molecular weight of 5,480.

Furthermore, a mixture of 20 g of polymer Ac '' and 23 mL of thionyl chloride were refluxed for 1 hour. The excess solid was removed to dissolve the residual solid in 90 mL of THF. 8.7 g of potassium in the solution t-butoxide was added gradually The reaction mixture was refluxed for 6 hours, cooled continuously and poured into water The solids obtained were collected by filtration, washed with water and dried in vacuo. Recrystallization from hexane gave the polymer (a-1c) according to the invention, which had a weight average molecular weight of 5,940 and a degree of dispersion of 3.0.

Synthesis Example 2c

(Synthesis of Polymer a-10c)

The same procedure as in Synthesis Example 1c was conducted except that 4-vinylcyclohexane was used instead of 5-vinylnorbornene. Thus, the polymer (a-10c) according to the present invention had a weight average molecular weight of 7,090 and a degree of dispersion of 3.0.

Synthesis Example 3c

Synthesis of Polymer (a-11c)

20 g of the polymer Ac "'obtained in Synthesis Example 1c was dissolved in 80 g of THF. The dissolved polymer was reacted with 5.2 g of 3,4-dihydro 2-H-pyran. The reaction product was coagulated with hexane to Polymer (a-11c) was obtained This polymer (a-11c) had a weight average molecular weight of 5,640 and a degree of dispersion of 3.0.

Synthesis Example 4c

(Synthesis of Polymer (a-23c))

The procedure was carried out in the same manner as in Synthesis Example 1c, except that? -naphthol was used instead of the phenol used as the starting material. Thus, a polymer (a-23c) according to the present invention was obtained. This polymer (a-23c) had a weight average molecular weight of 4,310 and a dispersion degree of 2.3.

(Examples 1c to 4c and Comparative Examples 1c to 4c)

(Production of Photosensitive Resin Composition)

The photosensitive resin composition was prepared from the components shown in Table 9. That is, the component is selected from polymers synthesized in Synthesis Examples 1c to 4c (a-1c), (a-10c), (a-11c) and (a-23c) and polymers synthesized in Synthesis Examples 6 and 7; Triphenylsulfonium triflate (PAG-1) as a photoacid generator; Acid-decomposable low molecular weight compounds synthesized in Synthesis Example 5; Nitrogen-containing basic compounds; Surfactants; And solvents were used. In Table 9, each dotted line means that the component is omitted.

The components were mixed together and the mixture was filtered through a 0.1 μm Teflon filter to prepare a photosensitive resin composition. The ingredients were mixed in each of the following amounts.

9.0g polymer

Photoacid Generator 0.10g

Acid Degradable Low Molecular Weight Compound 1.0g

0.01 g of nitrogen-containing basic compounds

0.003 g of surfactant

Solvent 55.12 g

polymer Photoacid generator Acid Degradable Low Molecular Compounds Nitrogenous Base Compound Surfactants menstruum Example 1c (a-1c) PAG-1 --- N-1 W-1 S-2 Example 2c (a-10c) PAG-1 --- N-2 W-1 S-1 Example 3c (a-11c) PAG-1 Compound a N-3 W-2 S-2 Example 4c (a-23c) PAG-1 Compound a N-1 W-2 S-1 Comparative Example 1c (a-1c) PAG-1 --- --- --- S-1 Comparative Example 2c (a-10c) PAG-1 --- --- W-1 S-1 Comparative Example 3c (b-1) PAG-1 --- N-1 W-1 S-1 Comparative Example 4c (b-2) PAG-1 Compound a N-3 W-2 S-2

The photosensitive resin composition thus prepared was evaluated for the development defect, the burnability and the dry etching property of the resist in the same manner as in the above-described examples. The evaluation results for development defects, evaluation results for burnability, and evaluation results for dry etching resistance are shown in Tables 10, 11, and 12, respectively.

Developing Defect I Development Defects II Example 1c 2 2 Example 2c 2 2 Example 3c One One Example 4c One 2 Comparative Example 1c 29 39 Comparative Example 2c 16 17 Comparative Example 3c 5 7 Comparative Example 4c 4 4

Residual Film Ratio (%) profile Limit resolution (㎛) Example 1c 99.7 A 0.16 Example 2c 99.4 A 0.15 Example 3c 99.9 A 0.13 Example 4c 99.9 A 0.13 Comparative Example 1c 99.7 A 0.16 Comparative Example 2c 99.4 A 0.15 Comparative Example 3c 98.2 B 0.28 Comparative Example 4c 97.4 B 0.23

Etching Rate (m / min) Example 1c 750 Example 2c 790 Example 3c 700 Example 4c 710 Comparative Example 1c 750 Comparative Example 2c 780 Comparative Example 3c 980 Comparative Example 4c 930

As shown in Table 10, the photosensitive resin composition according to the present invention each provides a resist film having almost no development defect. In contrast, the compositions obtained in Comparative Examples 1c and 2c which are not contained in at least one of the nitrogen-containing base compound (C) and the surfactant (D) have low development defects.

As shown in Table 11. The photosensitive resin composition according to the present invention has a very high residual film ratio, resolution and profile, respectively. In contrast, the compositions obtained in Comparative Examples 3c and 4c have low resolution and profile.

As shown in Table 12, the photosensitive resin composition according to the present invention each provides a resist film having excellent dry etching resistance. In contrast, the resist films obtained from the compositions of Comparative Examples 3c and 4c had insufficient dry etching resistance.

The present invention will be explained in more detail with reference to the following examples in which polymers having a partial structure represented by formula (Id) are used. However, the present invention is not limited to these examples.

Synthesis Example 1d

Synthesis of Polymer (a-1d)

780 g of phenol and 118 g of toluene were placed in a 2.5 L reaction vessel equipped with a reflux condenser and a Liebich cooler. The content was heated at 170 ° C. under reflux to distill 110 g of toluene. The system was dehydrogenated until it had a water content of 300 ppm. The system was then cooled to 70 ° C. and 2.6 g of boron trifluoride / phenol mixture was added. The temperature of the reaction mixture was maintained at 170 ° C, and polybutadiene having a water content of 258 g of 200 ppm (trade name, "Niseki Polybutadiene B-1000" Nippon Petrochemical Co., Ltd.) was gradually added dropwise for 1 hour. After the addition was completed, the reaction mixture was stirred at 70 ° C. for 1 hour. Then, 8 g of a hydrotalcite compound (trade name: "KW-1000") manufactured by Kyowa Chemical Co., Ltd. was added, and the reaction mixture was stirred for 30 minutes to inactivate the catalyst. The reaction mixture was filtered through filter paper applied with celite. The clean filtrate thus obtained was distilled at 200 ° C. under reduced pressure to obtain 280 g of a polymer Ad ′.

The solution prepared by dissolving 100 g of polymer of 200 g t-butanol and 3.5 g of nickel catalyst supported on diatomaceous earth was placed in an autoclave with a 1 L capacity. The atmosphere of the autoclave was replaced several times with nitrogen and several times with hydrogen. Thereafter, the hydrogen pressure in the autoclave was adjusted to 50 kg / cm 2, the components were heated while stirring and left at 200 ° C. for 10 hours.

After cooling, the resulting reaction mixture was filtered to remove the catalyst. The filtrate was dropped into 10 folds by weight of water to precipitate the polymer. The precipitated polymer was collected and dried in vacuo at 50 ° C. to give 85 g of polymer Ad ″. The polymer Ad ″ had a weight average molecular weight of 4,210. The hydrogenation degree of the phenol nucleus was calculated by IR and NMR spectrophotometer and found to be 95%.

Subsequently, 53 g of polymer Ad "and 30 g of 1,2-cyclohexanedicarboxylic anhydride were placed in a three-necked flask. 300 ml THF was added thereto to dissolve these components. 21 g of sodium hydroxide was added to this solution. The mixture was added dropwise gradually and the mixture was allowed to react for 6 hours at 40 ° C. The resulting reaction mixture was poured into water and crystallized, after removal of the remaining reaction product without reaction, the crystals were extracted by filtration and 50 ° C. Drying in vacuo afforded 47 g of polymer Ad ". This polymer Ad "had a weight average molecular weight of 5,400.

Furthermore, 20 g of the polymer Ad "and 22 ml of thionyl chloride were refluxed for 1 hour. The excess solid was removed to dissolve the residual solid in 90 ml of THF. 8.1 g of potassium t-butoxide was added to the solution. The reaction mixture was refluxed for 6 hours, continued to cool and poured into water The solid obtained was collected by filtration, washed with molar and dried under vacuum The purified reaction product was recrystallized from n-nucleic acid And Polymer (a-1d) according to the present invention, the polymer (a-1d) had a weight average Kb of 5,860 and a dispersion degree of 2.5.

Synthesis Example 2d

Synthesis of Polymer (a-5d)

20 g of the polymer Ad "'obtained in Synthesis Example 1d was dissolved in 80 g of THF. The dissolved polymer was reacted with 5.2 g of 3,4-hydro-2H-pyran. The reaction product was solidified with hexane to prepare the polymer according to the present invention ( a-5d) This polymer (a-5d) had a weight average molecular weight of 5,840 and a degree of dispersion of 2.5.

Synthesis Example 3d

Synthesis of Polymer (a-8d)

The same process as in Synthesis Example 1d was carried out except that fumaric anhydride was used instead of 1,2-cyclohexanedicarboxylic acid anhydride. Thus, a polymer (a-8d) according to the present invention was obtained. This polymer (a-8d) had a weight average molecular weight of 3,360 and a degree of dispersion of 2.1.

(Examples 1d to 4d and Comparative Examples 1d to 4d)

(Production of Photosensitive Resin Composition)

The photosensitive resin composition was prepared from the components shown in Table 1. Namely, the components used were polymers (a-1), (a-5d) and (a-8d) synthesized in Synthesis Examples 1d to 3d and polymers (b-1) and (b) synthesized in Synthesis Examples 5 and 6; A polymer selected from -2); Triphenylsulfonium triflate (PAG-1) as a photoacid generator; Acid-decomposable low molecular weight compounds synthesized in Synthesis Example 4; Nitrogen-containing basic compounds; Surfactants; And solvents were used. In Table 13, the dotted line means that the component is omitted.

The components were mixed together and the mixture was filtered through a 0.1 μm Teflon filter to prepare a photosensitive resin composition.

When using a phase, it was mixed in each of the following amounts.

9.0g polymer

Photoacid Generator 0.10g

Acid Degradable Low Molecular Weight Compound 1.0g

0.01 g of nitrogen-containing basic compounds

0.003 g of surfactant

Solvent 55.12 g

polymer Photoacid generator Acid Degradable Low Molecular Compounds Nitrogenous Base Compound Surfactants menstruum Example 1d (a-1d) PAG-1 --- N-1 W-1 S-2 Example 2d (a-5d) PAG-1 --- N-2 W-1 S-1 Example 3d (a-8d) PAG-1 Compound a N-3 W-2 S-2 Example 4d (a-1d) PAG-1 Compound a N-2 W-2 S-1 Comparative Example 1d (a-1d) PAG-1 --- --- --- S-1 Comparative Example 2d (a-5d) PAG-1 --- --- W-1 S-1 Comparative Example 3d (b-1) PAG-1 --- N-1 W-1 S-1 Comparative Example 4d (b-2) PAG-1 Compound a N-3 W-2 S-2

The photosensitive resin composition thus prepared was evaluated in the same manner as in the above-described Example to develop defects, to imageability of resist, and to dry etching resistance. The evaluation results of the development defects, the evaluation results of the imageability, and the evaluation results of the dry etching resistance are shown in Tables 14, 15, and 16, respectively.

Developing Defect I Development Defects II Example 1d 2 2 Example 2d 3 2 Example 3d 2 0 Example 4d One One Comparative Example 1d 27 43 Comparative Example 2d 12 16 Comparative Example 3d 5 7 Comparative Example 4d 4 4

Residual Film Ratio (%) profile Limit resolution (㎛) Example 1d 99.8 A 0.15 Example 2d 99.7 A 0.16 Example 3d 99.9 A 0.17 Example 4d 99.9 A 0.13 Comparative Example 1d 99.8 A 0.15 Comparative Example 2d 99.7 A 0.16 Comparative Example 3d 98.2 B 0.28 Comparative Example 4d 97.4 B 0.23

Etching Rate (m / min) Example 1d 740 Example 2d 780 Example 3d 710 Example 4d 700 Comparative Example 1d 740 Comparative Example 2d 780 Comparative Example 3d 980 Comparative Example 4d 930

As shown in Table 14, the photosensitive resin compositions according to the present invention each provide a resist film almost free of development defects. In contrast, the compositions obtained in Comparative Examples 1 and 2 which do not contain at least one of the nitrogen-containing base compound (C) surfactant (D) are low in developing defects.

As shown in Table 15, the photosensitive resin composition according to the present invention is very high in residual film ratio, resolution and profile, respectively. In contrast, the compositions obtained in Comparative Examples 3 and 4 are particularly low in resolution and profile.

As shown in Table 16, the photosensitive resin composition according to the present invention provides a resist film having excellent dry etching resistance. In contrast, the resist films obtained from the compositions of Comparative Examples 3 and 4 had insufficient dry etching resistance.

As indicated above, the positive photosensitive resin composition of the present invention is almost free from development defects when exposed to ArF excimer laser light, and is satisfactory in the residual film ratio, pattern profile and resolution. Moreover, the resist film obtained therefrom has excellent dry etching resistance. Thus, the composition can be efficiently used to form the micropatterns essential for producing semiconductor devices.

Having described the invention in more detail with reference to its embodiments, various changes and modifications can be readily made without departing from its spirit and scope.

Claims (16)

(A) a compound which generates an acid by irradiation of actinic rays, (B) a polymer having a partial structure represented by formula (Ia) (C) nitrogen-containing basic compounds, and (D) a positive photosensitive resin composition comprising at least one of a fluorine-type surfactant and a silicone-type surfactant: (Wherein R ₁ to R ₄ are each independently a hydrogen atom, a hydroxyl group, a carboxy group, an alkyl group, an alkoxy group, a substituted alkyl group, a substituted alkoxy group or R ₁ and R ₃ or R ₂ and R ₄ are bonded to each other to form a ring When, cycloalkyl group is represented; X represents a divalent organic group having 2 to 20 carbon atoms; R ₅ represents a hydrogen atom, an alkyl group, a substituted alkyl group, a cycloalkyl group, a substituted cycloalkyl group, or a group which acts as a group in which -COOR ₅ is decomposed by the action of an acid; Z represents an atomic group which combines with a carbon atom to form a cyclohexane or decalin ring.) The positive photosensitive resin composition according to claim 1, wherein the polymer (B) has a group decomposed by the action of an acid. The method of claim 1, further comprising a low-molecular, acid-decomposable dissolution inhibiting compound having at least one degradable group by the action of an acid, having a molecular weight of 2,000 or less to increase alkali solubility by the action of an acid. Resin composition. The positive photosensitive resin composition according to claim 1, wherein the actinic radiation is far ultraviolet rays having a wavelength of 220 nm or less. (A) a compound which generates an acid by irradiation with actinic rays, (B) a polymer having a partial structure represented by the following general formula (Ib), (C) nitrogen-containing basic compounds and (D) a positive photosensitive resin composition comprising at least one fluorine type surfactant and a silicone type surfactant: Wherein R ₁ to R ₄ are each independently a hydrogen atom, a hydroxyl group, a carboxy group, an alkyl group, an alkoxy group, a substituted alkyl group, a substituted alkoxy group, or R ₁ and R ₃ or R ₂ and R ₄ are bonded to each other to form a ring If cycloalkyl group; X represents a divalent organic group having 2 to 20 carbon atoms; R ₅ represents a hydrogen atom, an alkyl group, a substituted alkyl group, a cycloalkyl group, a substituted cycloalkyl group or a group which acts as a group in which -COOR ₅ is decomposed by the action of an acid; Z represents an atom that combines with a carbon atom to form cyclohexane or decalin) The positive photosensitive resin composition according to claim 5, wherein the polymer (B) has a group decomposed by the action of an acid. The method of claim 5, further comprising a low-molecular, acid-decomposable dissolution inhibiting compound having at least one degradable group by the action of an acid, having a molecular weight of 2,000 or less to increase alkali solubility by the action of an acid. Resin composition. The positive photosensitive resin composition according to claim 5, wherein the actinic radiation is far ultraviolet rays having a wavelength of 220 nm or less. (A) a compound which generates an acid by irradiation of actinic rays, (B) a polymer having a partial structure represented by the following formula (Ic), (C) a nitrogenous base compound, and (D) a positive photosensitive resin composition comprising at least one fluorine type surfactant and a silicone type surfactant: (Wherein R ₁ to R ₄ are each independently a hydrogen atom, a hydroxyl group, a carboxyl group, an alkyl group, an alkoxy group, a substituted alkyl group, a substituted alkoxy group or _one of R ₁ and R ₃ and R ₂ and R ₄ are bonded to each other When forming a ring, it represents a cycloalkyl group; X represents a divalent organic group having 2 to 20 carbon atoms; R ₅ represents a hydrogen atom, an alkyl group, a substituted alkyl group, a cycloalkyl group, a substituted cycloalkyl group or a group which acts as a group in which -COOR ₅ is decomposed by the action of an acid; Z represents a group of atoms which combine with carbon atoms to form a cyclohexane or decalin ring; Y is Wherein R ₆ and R ₇ each independently represent a hydrogen atom or a methyl group, and n represents 1 or 2). The positive photosensitive resin composition according to claim 9, wherein the polymer (B) is decomposed by the action of an acid. 10. The positive photosensitive resin according to claim 9, wherein the photosensitive resin contains a low-molecular, acid-decomposable dissolution inhibiting compound having at least one decomposable group by the action of an acid, and having a molecular weight of 2,000 or less, which increases alkali solubility by the action of an acid. Composition. The positive photosensitive resin composition according to claim 9, wherein the actinic radiation is far ultraviolet rays having a wavelength of 220 nm or less. (A) a compound which generates an acid by irradiation of actinic rays, (B) a polymer having a partial structure represented by the following general formula (Id), (C) a nitrogenous base compound, and (D) a positive photosensitive resin composition comprising at least one fluorine type surfactant and a silicone type surfactant: Wherein R ₁₁ represents a methyl group or an ethyl group; R ₁₂ and R ₁₃ each independently represent a hydroxy group, a carboxy group, an alkyl group, an alkoxy group, a substituted alkyl group, a substituted alkoxy group, or R ₁₂ and R ₁₃ combine with each other to form a ring When used, represents a cycloalkyl group; X ₁ represents a divalent organic group having from 2 to 20 carbon atoms; R ₁₄ represents a hydrogen atom, an alkyl group, a substituted alkyl group, a cycloalkyl group, a substituted cycloalkyl group or a -COOR ₁₄ -valent acid Group which acts as a group which is decomposed by The positive photosensitive resin composition according to claim 13, wherein the polymer (B) has a group decomposed by the action of an acid. A positive photosensitive compound according to claim 13, which contains a low-molecular, acid-decomposable dissolution inhibiting compound having at least one decomposable group by the action of an acid and having a molecular weight of 2,000 or less which increases alkali solubility by the action of an acid. Resin composition. The positive photosensitive resin composition according to claim 13, wherein the actinic radiation is far ultraviolet rays having a wavelength of 220 nm or less.